Sumitra has an average of 56% on her first 7 examinations. How much should she make on her eighth examination to obtain an average of 60% on 8 examinations?
Options:
(A) 88%
(B) 78%
(C) 98%
(D) Cannot be determined
(E) None of these

Since the weight age of eighth examination is not known, hence can not be determine So the answer is: (D).

A train running at the speed of 30 km/hr crosses a pole in 9 seconds. Find the length of the train?
Options:
(A) 75
(B) 65
(C) 25
(D) 288
(E) 212

Speed = 30*(5/18) m/sec = 25/3 m/sec
Length of Train (Distance) = Speed * Time
(25/3) * 9 = 75 meter So the answer is: (A).

Look at this series: 7, 10, 8, 11, 9, 12, ... What number should come next?
Options:
(A) 10
(B) 12
(C) 7
(D) 8
(E) 9

This is a simple alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted. So the answer is: (A).

The speed of a train is 90 kmph. What is the distance covered by it in 10 minutes?
Options:
(A) 277
(B) 266
(C) 300
(D) 767
(E) 211
1/2:1/3:1/4 = 6:4:3
3/13*1300 = 300 So the answer is: (C).