X can finish a work in 18 days. Y can finish the same work in 15 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 3
(B) 5
(C) 6
(D) 8
(E) 9

Work done by X in 1 day = 1/18
Work done by Y in 1 day = 1/15
Work done by Y in 10 days = 10/15 = 2/3
Remaining work = 1 2/3 = 1/3
Number of days in which X can finish the remaining work = (1/3) / (1/18) = 6 So the answer is: (C).

A train running at the speed of 60 km/hr crosses a pole in 9 sec. What is the length of the train?
Options:
(A) 350 m
(B) 250 m
(C) 300 m
(D) 148 m
(E) 150 m

Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 9 = 150 m So the answer is: (E).

There are different 10 circles. What is the number of the greatest possible points with which the circles intersect?
Options:
(A) 90
(B) 100
(C) 110
(D) 180
(E) 200

Maximum points of intersection between n different circles = n*(n - 1) = 10*9 = 90 So the answer is: (A).

The speed of a car is 90 km in the first hour and 42 km in the second hour. What is the average speed of the car?
Options:
(A) 89 kmph
(B) 92 kmph
(C) 75 kmph
(D) 65 kmph
(E) 66 kmph
S = (90 + 42)/2 = 66 kmph So the answer is: (E).