Questions from Mathematics
31. A train of length 270 metres crosses a telegraph post in 18 seconds. The speed of the train is
(A) 54 km/hr
(B) 35 km/hr
(C) 45 km/hr
(D) 60 km/hr
32. How much time does a train, 280m long, running at a speed of 72 km/hr, take to cross a bridge of 220m long?
(A) 25 seconds
(B) 30 seconds
(C) 35 seconds
(D) 60 seconds
35. A sum of money doubles itself in 5 years. The number of years, it would treble itself is:
(A) 10 years
(B) 15 years
(C) 20 years
(D) 25 years
36. A and B can do a piece of work in 18 days, B and C in 24 days, A and C in 36 days. In what time can they do it if all of them working together?
(A) 8 days
(B) 16 days
(C) 40 days
(D) 24 days
