RRB NTPC 2019-20: Mathematics Mock Test with Answers (30 Marks) |
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1. The difference of two numbers is 1365. On dividing the larger number by the smaller, we get 6 as quotient and 15 as remainder. What is the smaller number?
a) 1635
b) 270
c) 290
d) 1700
Answer: (b)
Explanation: Suppose the smaller number is x, then the larger number = (x+ 1365)
Therefore, x+1365 = 6x+ 15 5x = 1350 x = 270.
Thus, the smaller number = 270.
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2. What is the smallest five digit number that is divisible by 111?
a) 10100
b) 10111
c) 10001
d) 10101
Answer: (d)
Explanation: The smallest five digit number is 10000
In 10000 ÷111 the remainder is 10. Thus By adding 101 (111-10) to 10000, 10101 is the smallest 5 digit number divisible by 111.
3. The mean marks of 10 men in a class are 70 Kg, whereas the mean marks of 15 women is 60. The mean marks of all the 25 people are:
a) 64
b) 60
c) 55
d) 52
Answer: (a)
Explanation: The mean marks of 10 men = 70
Total marks of 10 men = 70 × 10 = 700
The mean marks of 15 women = 60
Total marks of 15 women = 60 × 15 = 900
∴ Sum of the total marks of 25 people = 700 + 900 = 1600
∴ The mean marks of all the 25 people =1600/25=64
4. In Ajit’s opinion, his weight is greater than 65 kg but less than 72 Kg. his brother does not agree with Ajit and he thinks that Ajit’s weight is greater than 60 Kg but less than 70 Kg. His mother’s view is that his weight cannot be greater than 68 kg. If all of them are correct in their estimation, what is the average of different probable weights of Ajit?
a) 68 Kg
b) 70 Kg
c) 66.5 Kg
d) 63.5 Kg
Answer: (d)
Explanation: Let Ajit’s Weight be S kg
According to Ajit, 65 < S < 72
According to Ajit’s brother, 60 < S < 70
According to Ajit’s mother, S < 68
The values satisfying all the above conditions are 66 and 67
5. The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75 of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?
a) Rs. 20 and Rs. 26
b) Rs. 16 and Rs. 22
c) Rs. 10 and Rs. 16
d) Rs. 20 and Rs. 32
Answer: (c)
6. Two friends work in same company and ratio of their salaries is 3 : 5. First friend gets promoted after a year and his salary is increased by one third of the salary of his friend. Find the ratio of their current salaries.
a) 11 : 15
b) 2 : 3
c) 14 : 15
d) None of these
Answer: (C)
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7. Amit got thrice as many marks in Maths as in English. The proportion of his marks in Maths and History is 4:3. If his total marks in Maths, English and History are 250, what are his marks in English?
a) 120
b) 90
c) 40
d) 80
Answer: (c)
8. A man sells half of his articles at a gain of 25% and the remaining at cost price. What is the profit or loss percentage incurred?
a) 12.5%
b) 15%
c) 18.75%
d) 12.75%
Answer: (a)
9. A trader offers his customers 15% discount and still makes a profit of 25%. What is the actual cost to him of an article marked Rs. 350.
a) Rs. 238
b) Rs. 338
c) Rs. 438
d) None of these
Answer: (a)
10. A whole – seller allows a discount of 30 % on the list price to a retailer. The retailer sells at 10 % discount on the list price. If the customer paid Rs. 63 for an article, what profit is made by the retailer?
a) Rs. 9
b) Rs. 4
c) Rs.8
d) Rs.6
Answer: (b)
Explanation: The customer pays Rs. 63 after a discount of 10%.
If the list price is Rs. x, then
X – 10% of x = 63
X = Rs. 70
Therefore, the list price = Rs. 70
The retailer buys the article at 30 % discount
= 70 – 30 % of 70
=Rs. 59
Then the profit for the retailer = Rs. (63 -59) = Rs.4.
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11. A book costs Rs.480. If it is sold at a loss of 55%. What will be its cost price as a percentage of its selling price?
a) 222.22%.
b) 212.22%.
c) 202.22%.
d) None of these
Answer: (a)
Explanation: A loss of 55 % means cost price is 100 corresponding to a selling price of 45.
Cost price as a percentage of selling price = (100/45 × 100) = 222.22%.
12. Find out the % change that will occur in area if the length of rectangle is increase by 30% and the width is decrease by 15%
a) 10.5
b) 11.5
c) 12.5
d) 13.5
Answer: (a)
Explanation:
Length and width be 100 cm & 100 cm respectively
Area = 10000 sq.cm.
After change length by 30% new length = 130 cm.
New width = 85 cm.
Area = 130 × 85 sq.cm.
13. A man lends one of his prize money of Rs 20,000 to four persons. If he gets an interest of 12% on Rs 6000 from the first person, 8% for another R 6000, 4% on Rs 4000, what rate must he get on the remaining part to make his average annual interest 16%?
a) 28
b) 46
c) 36
d) 42
Answer: (b)
14. An amount of Rs 841 is divided among two persons so that they get equal amounts at a rate of 5% after 6 years and 8 years respectively. What is the smaller amount?
a) Rs 400
b) Rs 421
c) Rs 441
d) Rs 401
Answer: (a)
15. A river runs at 3 kmph. if the time taken by a man to row his boat upstream is twice the time taken by him to row it downstream , then at what speed can he row his boat in still water?
a) 9 kmph.
b) 12 kmph.
c) 10 kmph.
d) None of these
Answer: (a)
Explanation: let x be the speed of the boat in still water and speed of the river = 3 kmph
Speed upstream = x- 3 kmph
Speed downstream = x+3 kmph
(x-3)2t = (x+ 3) t
2 (x- 3) = x+ 3
X= 9 kmph.
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16. A man on a platform sees that a train going in one direction takes 10 s to pass him, and a train of same length going in the opposite direction takes 15s to pass him. What is the time taken by two trains to pass one another if the length of the trains is 200 m each?
a) 15 S
b) 16 S
c) 12 S
d) None of these
Answer: (c)
17. A can complete a work working 4 hours a day in 5 days and B can complete the same work in 5 days working 4 hours a day. If both work together for 8 hours a day, how many days will it take to complete the job?
Answer: (b)
18. Tom takes 18 days to finish a job. Mike is 20% more efficient than Tom. What number of days would Mike take to finish the job?
(a) 12
(b) 10
(c) 15
(d) 14
Answer: (c)
Explanation:
Efficiency ratio of Mike to tom = 120:100 = 6:5
Let the number of days Mike takes be x. So,
6:5:: 18: x
x= 5 × (18/6)
No of days= (Efficiency of Tom × No of days Tom need)/ Efficiency of Mike
x= 15 days
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19. P, Q, R, S, and T are 5 consecutive even numbers. If the sum of P and S is 150, what is the sum of all the numbers?
a) 320
b) 340
c) 360
d) 380
Answer: (d)
Explanation:
P = P
Q = P + 2
R = P + 4
S = P + 6
And T = P + 8
According to question: P + S = 150
P + P + 6 = 150
2P = 144
P = 72
Sum of all numbers = P + Q + R + S + T = 72 + 74 + 76 + 78 + 80
= 380
20. Find out the age of elder son if he is 4 years elder to younger son 1– years ago there were 6 members in the family and the average age of them were 29 years. At present there are 8 members as two sons were born and the average age is increased by 1 year at present.
a) 5
b) 6
c) 7
d) 8
Answer: (a)
Explanation:
10 years ago total age of family
= 29 × 6 = 174 years
Total age of 5 members of family at present
= 174 + 10 × 6 = 234 years
Total age of family at present
= 8 × (29 + 1) = 8 × 30 = 240
Hence sum of age of two children
= 240 – 234 = 6 years
Hence age of elder son = 5 years
Age of Younger son = 1 year.
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21. Find out the total age of all the boys if average age of boys is 2% of the total number of girls and the ratio of boys to girl is 3:4 and the number of Student in a school is 1225.
a) 7350
b) 7400
c) 7355
d) 7200
Answer: (a)
22. The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75 of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?
a) 12 and 19.2
b) 14 and 20
c) 10 and 16
d) None of these
Answer: (c)
23. A Petrol pump owner mixes 10% kerosene in petrol but he is not content with it so he again mixes 10% more kerosene in the previous mixture. What is the profit percentage of Petrol pump owner if he sells it at cost price?
a) 11.11%
b) 20%
c) 21%
d) 12.1%
Answer: (c)
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24. A shopkeeper sold a book at Rs. 144 in such a way that his percentage profit is same as the cost price of the book. If he sells it at twice the percentage profit of its previous percentage profit then new selling price will be:
a) Rs.208
b) Rs.250
c) Rs.192
d) Rs.180
Answer: (a)
Explanation: From taking options,
I.e. CP = 80
i. e New SP = 80 + 2 X 64 = 208
25. An amount of Rs 841 is divided among two persons so that they get equal amounts at a rate of 5% after 6 years and 8 years respectively. What is the smaller amount?
(a) Rs 400
(b) Rs 421
(c) Rs 441
(d) Rs 401
Answer: (a)
26. How long a train of length 200 m running at 120 kmph will take to cross a motor cycle moving in the same direction at 12 kmph?
(a) 5 seconds
(b) 6 seconds
(c) 2 seconds
(d) 10 seconds
Answer: (a)
Explanation:
Time = Length of the train/ Relative speed between the two bodies
Relative speed= 120 – 12 = 108 kmph
Converting kmph to mps,
108 * 5/18 = 30 mps
Time= 150/30
= 5 seconds
27. A boat speeds 1 and a half hours down the stream and 2 and a half hours up the stream of 30 km. What is the speed of the water current in kmph?
(a) 5 kmph
(b) 20 kmph
(c) 12 kmph
(d) 4 kmph
Answer: (d)
Explanation:
Speed upstream= 30 * (2/5) (Distance/Time) =12 kmph
Speed downstream= 30* (2/3) = 20 kmph
Speed of water current= 1/2* (Downstream speed- Upstream Speed)
= (1/2) * (20 - 12) = 4 kmph
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28. A man and 2 boys can finish a job in 5 days and the same job can be done in 3 days by 2 men and a boy. How many days does it take 2 men and boys each to finish the job?
(a) 16/45
(b) 45/16
(c) 4
(d) 15/16
Answer: (b)
29. An inlet pipe fills water in a reservoir at the rates of 0.1 litres/sec. When the reservoir is full, the inlet is opened but due to a leak at the bottom, it is emptied in 12 hours. What is the capacity of the reservoir, if it is known that the leak can empty the full reservoir in 8 hours had there been no inlet?
a) 7500
b) 7690
c) 8400
d) 8640
Answer: (d)
30. The diagram below represents three circular water drums, each of diameter 4 m. The three drums are touching as shown. Find, in metres, the perimeter of the rope encompassing the three drums.
a) 2π +6
b) 3π +4
c) 4π +6
d) 6π +6
Answer: (d)
Explanation:
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