question: John has $2500 in his bank account that earns 10% interest every year. How much will be in John's bank account after one year?
Options:
(A) $2600
(B) $3000
(C) $2250
(D) $2750
(E) $3500
answer: Stream of consciousness: Final number = Initial number + 20%(original number) = 2500 + 10%(2500) = 2500 + 250 = 2750. The answer is (D).


q: A pipe can fill a cistern in 20 minutes whereas the cistern when fill can be emptied by a leak in 30 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17 minutes
(B) 87 minutes
(C) 60 minutes
(D) 27 minutes
(E) 11 minutes
a: Stream of consciousness: 1/20 - 1/30 = 1/60
60 minutes The answer is (C).


question: If X is the sum of first 20 positive even integers and Y is the sum of first 20 positive odd integers, what is the value of x-y?
Please try to explain your answers
Options:
(A) 0
(B) 20
(C) 50
(D) 75
(E) 100
answer: Stream of consciousness: 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 20 positive even integers minus the sum of first 20 positive odd integers will be 20. The answer is (B).


q: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 7 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
a: Stream of consciousness: Speed downstream = d/t = 85/(2 1/2) = 34 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (34 - 18)/2 = 8 kmph The answer is (D).


question: Fill in the blank with the correct number in this number series: 6, 45, 14, 40, __, 35, 30, ?
Options:
(A) 13
(B) 22
(C) 24
(D) 27
(E) 18
answer: Stream of consciousness: This is a simple alternating subtraction and addition series; The first series begins with 6 and adds 8; the second begins with 45 and subtracts 5, and so on. The answer is (B).


question: In a certain animal population, for each of the first 3 months of life, the probability that an animal will die during that month is 1/10. For a group of 200 newborn members of the population, approximately how many would be expected to survive the first 3 months of life?
Options:
(A) 140
(B) 146
(C) 152
(D) 162
(E) 170
answer:

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: Number of newborns that can die in first month = 1/10 * 200 = 20
Survived = 180
Number of newborns that can die in second month = 1/10 * 180 = 18
Survived = 162
Number of newborns that can die in third month = 1/10 * 162 = 16
Survived = 146 The answer is (B).