# Railway Exam Maths Questions and Answers – RRB ALP & RRB Group-D

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## Railway Maths Questions and Answers:

Download Mathematics questions and answers for Railway exams of RRB ALP and RRB Group D. Important maths railway problems PDF.

Question 1:Â 12 copies of a book were sold for Rs. 1800, thereby gaining the cost price of 3 copies. The cost price of a copy is

a) Rs. 120
b) Rs. 150
c) Rs. 1200
d) Rs. 1500

Question 2:Â A sum of money put out at compound interest amounts to Rs. 16900 in 2 years and to Rs. 17576 in 3 years. Find the rate of interest per annum.

a) 4%
b) 5%
c) 10%
d) 6%

Question 3:Â On what sum of money will the for 3 years at 5% per annum to Rs. 630.50.

a) Rs. 1200
b) Rs. 1261
c) Rs. 4000
d) Rs. 3000

Question 4:Â A sum of Rs. 625 is made up of 80 currency notes which are of either Rs. 10 or Rs. 5 denomination. The number of Rs. 10 notes are

a) 35
b) 45
c) 40
d) 30

Question 5:Â A certain job was assigned to a group of men to do in 20 days. But 12 men did not turn up for the job and the remaining men did the job in 32 days. The original number of men in the group was

a) 32
b) 34
c) 36
d) 40

Question 6:Â A certain number of men can do a work in 60 days. If there were 8 men more it could be finished in 10 days less. How many men were there in the beginning ?

a) 40
b) 35
c) 45
d) 50

Question 7:Â 12 men and 18 boys working $7\frac{1}{2}$ hours a day can do a certain work in 60 days. If one man works equal to 2 boys. Then the number of boys required to help 21 men to do twice the work in 50 days, working 9 hours a day, will be

a) 30
b) 42
c) 48
d) 90

Question 8:Â The average expenditure of a man for the first five months is Rs. 1200 and for the next seven months is Rs. 1300. Find his monthly average income if he saves Rs. 2900 during the year ?

a) Rs. 1500
b) Rs. 1475
c) RS. 1450
d) Rs. 1425

Question 9:Â The average temperature for monday, Tuesday and wednesday was 40Â°C. The average for Tuesday, wednesday and Thursday was 41Â°C. If on Thursday temperature is 45Â°C, What was it on monday ?

a) 40Â°C
b) 41Â°C
c) 42Â°C
d) 43.5Â°C

Question 10:Â Of the three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is 44, the largest number is

a) 24
b) 72
c) 36
d) 108

Solutions forÂ Railway Exam Maths Questions and Answers:

Solutions:

SP of 12 books=1800
SP=CP + Profit
Given, Profit of 12 books=3CP
âˆ´1800=12CP + 3CP
15CP=1800
CP=120

Let x be the principal amount and r be the compound interest.
The amount after first year =$x + xr$
the amount after second year=$(x + xr) +(xr + xr^{2})=x+2xr + xr^{2}=x(1+r)^{2}$=16900 -(1)
Similarly, the amount after third year =$x(1 + r)^{3}$= 17576 -(2)
dividing 2 by 1 we get,
1+r=1.04
r=.04
Thus the interest is 4%.

$P (1 + .05) ^ {3}$ – P= 630.5
Solving for P, we get P = 4000

Let there be x 10 rupee notes in the sum. The number of 5 rupee notes = 80 – x
The sum = 10x + (80 – x)* 5 = 625
So, x = 45

Let there be x men initially. They were supposed to complete the work in 20 days.
When 12 men didn’t show up the work was done in 32 days
So, x- 12 men did the work in 32 days
But x-12 men were supposed to take 20x/ (x-12) days
So, 20 x/ (x-12) = 32
so, x = 32

Let there be m men originally to work in 60 days
If the men were m + 8, the work would be completed in 50 days.
(m+8)/m = 60/50
So, m = 40

2 boys = 1 man
So, 21 men can do work W is 60 days working 7.5 hours per day.
to do 2W, 42 men are needed.
To do the job in 50 days, 60 x 42 / 50 men are needed.
To do the job working 9 hours a day, 7.5/9 x 60 x42/50 men are needed
= 42 men
We only have 21 men so, we get 42 extra boys to get the work needed for the 21 extra men.

Let his monthly salary be x rupees.
So, 5 (x – 1200) + 7 (x-1300) = 2900
12x – 6000 – 9100 = 2900
So, x = 18000/12 = 1500