q: From among the 31 students in a class, one leader and one class representative are to be appointed. In how many ways can this be done?
Options:
(A) 1360
(B) 1260
(C) 1060
(D) 1160
(E) 930
a: Stream of consciousness: There are 31 students and every one has equal chance of being selected as a leader. Hence, the leader can be appointed in 31 ways. When one person is appointed as leader, we are left with 35 students. Out of these 30 teachers, we can select one class representative. So, a class representative can be selected in 30 ways. Hence, the number of ways in which a leader and class representative can be selected = 31 x 30 = 930 The answer is (E).


question: The flow of water through a drainage pipe was monitored for a 3-hour period. In the second hour, the rate of flow was 36 gallons per hour, which was 50 percent faster than the rate of flow for the first hour. If 25 percent more water flowed through the pipe in the third hour than it did in the second, how many gallons of water flowed through the pipe during the entire three hours?
Options:
(A) 106.25
(B) 105.5
(C) 105.75
(D) 106
(E) 105.0
answer: Stream of consciousness: Rate of flow of water in second hour = 36 gallons per hour
Rate of flow of water in first hour = 36/(3/2) = 24 gallons per hour
Rate of flow of water in third hour = (125/100)* 36 = (5/4) * 36 = 45 gallons per hour
Number of gallons of water that flowed through the pipe during the entire 3 hours = 24+36+45 = 105 gallons The answer is (E).


q: Ten telegenic contestants with a variety of personality disorders are to be divided into two “tribes” of three members each, tribe A and tribe B, for a competition. How many distinct groupings of two tribes are possible?
Options:
(A) 120
(B) 126
(C) 252
(D) 1200
(E) 1260
a: Stream of consciousness: My ans is 10C3 = 120 The answer is (A).


question: From the set of numbers x, y, t, z, s and w, how many different combinations can we have without the t in them? Ex:. (x,y), (x), (w,z,y,x,s), etc and (x,y)=(y,x)
Options:
(A) 10
(B) 14
(C) 15
(D) 16
(E) 31
answer: Stream of consciousness: Another way: Any letter (x, y, z, w, s) can be included or not. So, we have 2^5 combinations - 1 empty combination = 31 combinations The answer is (E).


q: Train A & B leave from same station and reaches same destination but train A leaves half an after Train B & travels 2 times faster than B. Total distance is 100 miles & train B travels 50 miles/hour. Which train reaches the destination first & what is the time difference between the train
Options:
(A) Train A reaches 30 minutes before Train B
(B) Train B reaches 30 minutes before Train A
(C) Train A reaches 60 minutes before Train B
(D) Train B reaches 60 minutes before Train A
(E) None of the above
a: Stream of consciousness: Time taken for train A = 30 minutes + d1/s1 = 30 minutes + 100 / 100 = 1 hours 30 minutes
Since Train B travels 50 miles / hour ; train A travels twice the speed of B which gives s1 = 100 miles/ hour
Time taken for train B = d2/s2 = 100 / 50 = 2 Hours
So Train A reaches 30 minutes before Train B The answer is (A).


q: Which of the following expressions are different in value?
(A) (2x + 3y)2
(B) (2x + y)2 + 8y(x + y)
(C) (2x – y)2 – 8y(x + y)
(D) 22(x + y)2 + 4xy + 5y2
Options:
(A) A and B
(B) B and C only
(C) A, B and D only
(D) B and D only
(E) All are different
a:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: All others are equal except (C). The answer is (B).