(Ans). (E)
(Question). The average of ten numbers is 210. The average of first five numbers is 40 and the average of last four numbers is 200. What is the middle number?
Options:
(A) A) 200
(B) B) 2000
(C) C) 800
(D) D) 2100
(E) E) 1100
(CoT). The total of ten numbers = 10X210 = 2100
The total of first 5 and last 4 numbers is = 5 X 40+4 X 200 = 1000
So, the middle number is (2100 - 1000 ) = 1100

(Ans). (C)
(Question). The length of each side of an equilateral triangle having an area of 43 cm2 is?
Options:
(A) 1/8
(B) 1/9
(C) 1/5
(D) 1/23
(E) 1/2
(CoT). Six persons can be arranged in a row in 6! ways. Treat the three persons to sit together as one unit then there four persons and they can be arranged in 4! ways. Again three persons can be arranged among them selves in 3! ways. Favourable outcomes = 3!4! Required probability = 3!4!/6! = 1/5

(Ans). (C)
(Question). 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
(CoT). 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

(Ans). (D)
(Question).
There is a 100 pound watermelon laying out in the sun. 99 percent of the watermelon's weight is water. After laying out for a few hours 98 percent of the watermelon's weight is water.
How much water evaporated?
Options:
(A) 20
(B) 30
(C) 40
(D) 50
(E) 10
(CoT). In the beginning it is 99 pounds water and 1 pound other stuff. At the end the 1 pound other stuff is 2 percent so the total weight is 50 pounds. 50 pounds - 1 pound other stuff = 49 pounds water. So 99 pounds - 49 pounds = 50 pounds water lost.