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# Maths Questions for DSSSB Exam 2017

Q1. A bus moving at a speed of 45 km/hr overtakes a truck 150 m ahead going in the same direction in 30 seconds. The speed of the truck is
(a) 27 km/hr
(b) 24 km/hr
(c) 25 km/hr
(d) 28 km/hr

Q2. A train 300 m long passed a man walking along the line in the same direction at the rate of 3 km/hr in 33 seconds. The speed of the train is
(a) 30 km/h
(b) 32 km/h
(c) 32 8/11 km/h
(d) 35 8/11 km/h

Q3. A train, 240 m long crosses a man walking along the line in opposite direction at the rate of 3 km/h in 10 seconds. The speed of the train is
(a) 63 km/h
(b) 75 km/h
(c) 83.4 km/h
(d) 86.4 km/h
Q4. Two trains of length 70 m and 80 m are running at the speed of 68 km/hr and 40 km/hr respectively on parallel tracks in opposite directions. In how many seconds will they pass each other?
(a) 10 sec
(b) 8 sec
(c) 5 sec
(d) 3 sec

Q5. Two trains of length 137 m and 163 m are running with speed of 42 km/hr and 48 km/hr respectively towards each other on parallel tracks. In how many seconds will they cross each other?
(a) 30 sec
(b) 24 sec
(c) 12 sec
(d) 10 sec

Q6. The average of marks obtained by 120 candidates was 35. If the average of marks of passed candidates was 39 and that of failed candidates was 15, the number of candidates who passed the examination is:
(a) 100
(b) 110
(c) 80
(d) 70

Q7. The profit earned after selling an article for Rs. 1754 is the same as loss incurred after selling the article for Rs. 1492. What is the cost price of the article?
(a) Rs. 1623
(b) Rs. 1523
(c) Rs. 1689
(d) Rs. 1589

Q8. The average expenditure of a man for the first five months is Rs. 3600 and for next seven months it is Rs. 3900. If he saves Rs. 8700 during the year, his average income per month is:
(a) Rs. 4500
(b) Rs. 4200
(c) Rs. 4050
(d) Rs. 3750

Q9. The average of two numbers A and B is 20, that of B and C is 19 and of C and A is 21. What is the value of A?
(a) 24
(b) 22
(c) 20
(d) 18

Q10. 12 men can finish a project in 20 days. 18 women can finish the same project in 16 days and 24 children can finish it in 18 days. 8 women and 16 children worked for 9 days and then left. In how many days will 10 men complete the remaining project?
(a) 10 1/2
(b) 10
(c) 9
(d) 11 1/2

Solutions:
S1. Ans.(a)
Sol. 150=(45-x)×5/18×30
18 = 45 – x
x = 27 km/h
S4. Ans.(c)
Sol.
⇒ Relative speed in opposite direction = (68 + 40) ⇒ 108 km/h
⇒ Time taken by trains to cross each other
=(70+80)metre/(108 km/hr)
⇒150/(108×5/18)
⇒150/30 = 5 sec
S5. Ans.(c)
Sol.
Crossing time =((137+163) metres)/((42+48) kmph)
Crossing time =300/(90 × 5/18)
= 12 sec.
S6. Ans.(a)
Sol. Let, the number of candidates who passed = x
Then,( 39 × x) + 15×(120-x)=120 × 35
∴ 24x = 4200 – 1800
Or, x=2400/24
x = 100.
S8. Ans.(a)
Sol. Total expenditure for the first five months = 5 × 3600 = Rs. 18000
Total expenditure for the next seven months = 7 × 3900 = Rs. 27300
Savings = Rs. 8700
Total income during the year
= 18000 + 27300 + 8700 = Rs. 54000
Average income per month =54000/12 = Rs. 4500.
S9. Ans.(b)
Sol. According to the question,
(A + B)/2=20
⇒ A + B = 40 …(i)
(B + C)/2=19
⇒ B + C = 38 …(ii)
(C + A)/2=21
⇒ C + A = 42 …(iii)
Adding (i), (ii) and (iii), we get
∴ 2A + 2B + 2C = 120
⇒ A + B + C = 60
∴ A = (A + B + C) – (B + C) …(iv)
= 60 – 38 = 22
S10. Ans.(b)
Sol. 12M × 20 = 18W × 16 = 24C × 18
5M : 6W : 9C
Work done by 8 women and 16 children
(8W+16C)×9 = (8×5/6 M+16×5M/9)×9
=(40M/6 + 80M/9)×9 = 140 M
Remaining work = 12M × 20 – 140M = 240M – 140M = 100M
10 men will complete the work in 100/10 days = 10 days