Question: A train 460 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40
(B) 87
(C) 48
(D) 21
(E) 14
Answer: Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 460 + 140 = 600 m
Required time = 600 * 2/25 = 48 se
The answer is (C).

Question: Calculate the circumference of a circular field whose radius is 8 centimeters.
Options:
(A) 18 cm
(B) 1 cm
(C) 8 cm
(D) 19 cm
(E) 28 cm
Answer: Circumference C is given by
C = 2r = 2*9 = 18 cm
The answer is (A).

Question: If X is the sum of first 40 positive even integers and Y is the sum of first 40 positive odd integers, what is the value of x-y?
Please try to explain your answers
Options:
(A) 0
(B) 25
(C) 40
(D) 75
(E) 100
Answer: First even minus first odd = 2-1 = 1;
The sum of first 2 even integers minus the sum of first 2 odd integers = (2+4)-(1+3) = 2;
The sum of first 3 even integers minus the sum of first 3 odd integers = (2+4+6)-(1+3+5) = 3;
We can see the patterns here, so the sum of first 40 positive even integers minus the sum of first 40 positive odd integers will be 40.
The answer is (C).

Question: In how many different ways can the letters of the word 'PREPTY' be arranged?
Options:
(A) 280
(B) 290
(C) 300
(D) 340
(E) 360
Answer:
Number of ways = 61/21 6X5X4X3X2X1 - 360
The answer is (E).