Q: A monkey standing on the ground wants to climb to the top of a vertical pole of 15 m. He climbs 5 m in 1 s and slips downward 3 m in next second. He again climbs 5 m in 1 s and slips by 3 m in the next second and so on. The time taken by the monkey to climb at the top of pole is
(a) 2 s
(b) 3 s
(c) 9 s
(d) 11 s
Ans: (d)