(Ans). (B)
(Question). Four of the following five parts numbered (a), (b), (c), (d) and (e) in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is the answer.
Options:
(A) xy2 – x2y + 2x2y2
(B) xy2(1 – 2x)  + x2y(2y – 1) 
(C) xy2(1 + x)  – x2y(1 – y) 
(D) xy[y(1 + x)  – x(1 – y) ]
(E) xy(y – x + 2xy) 
(CoT). The other parts are equal to xy2 – x2y + 2x2y2.


(Ans). (D)
(Question). 80 370 ? 1550 2440 3530
Options:
(A) 900
(B) 840
(C) 750
(D) 860
(E) 960
(CoT). 10^2 - 20 = 80
20^2 - 30 = 370
30^2 - 40 = 860
40^2 - 50 = 1550
50^2 - 60 = 2440
60^2 - 70 = 3530.


(Ans). (B)
(Question). The average height in a group of 4 people is 175 cm. If the average height increased when 2 more people were added to the group, which of the following cannot be the heights of the two new people?
Options:
(A) 179 cm and 172 cm
(B) 181 cm and 169 cm
(C) 173 cm and 178 cm
(D) 176 cm and 176 cm
(E) 174 cm and 177 cm
(CoT). Denote X as the sum of the heights of the two new people. From the stem it follows that (700+X)6>175. This reduces to X>350. Only the heights from B add up to 350 cm. All other pairs add up to more than 350 cm.


(Ans). (C)
(Question).
The average of 13 result is 60. Average of the first 7 of them is 57 and that of the last 7 is 61. Find the 8th result?
Options:
(A) 35
(B) 37
(C) 46
(D) 48
(E) 50
(CoT). Sum of all the 13 results = 13 * 60 = 780
Sum of the first 7 of them = 7 * 57 = 399
Sum of the last 7 of them = 7 * 61 = 427
So, the 8th number = 427 + 399 - 780 = 46.