q: The ages of Rahul and Madhan differ by 16 years. Six years ago, Madhan’s age was thrice as that of Rahul’s,find their present ages
Options:
(A) 14 years, 30 years
(B) 12 years, 28 years
(C) 16 years, 34 years
(D) 18 years, 38 years
(E) none of these
a: Stream of consciousness: Let Rahul’s age = x years
So, Madhan’s age = ( x + 16 )years
Also, 3(x - 6) = x + 16 - 6 or, x = 14
Rahul’s age = 14 years
And, Madhan’s age 14 + 16 = 30 years The answer is (A).


question: The measure of the side of a square is doubled. If x represents the perimeter of the original square, what is the value of the new perimeter?
Options:
(A) 2x
(B) 4x
(C) 9x
(D) 12x
(E) 27x
answer: Stream of consciousness: Original perimeter = x
Hence original side = x/4
New side = 2x/4
New perimeter = 4*2x/4 = 2x The answer is (A).


q: In a race of 600 metres, A can beat B by 60 metres and in a race of 500 metres, B can beat C by 50 metres. By how many metres will A beat C in a race of 400 metres?
Options:
(A) 76 metres
(B) 80 metres
(C) 70 metres
(D) 84 metres
(E) None
a: Stream of consciousness: A runs B runs C runs
600 metres race 600m 540 m
500 metres race 500 m 450m
Combing ratio A runs B runs C runs
300metres - 2700meters - 2430metres
Unitary A runs B runs C runs
Method 400mtres - 360 metres - 324 metres
? A beats C by 400-324 = 76 metres. The answer is (A).


question: A bag contains 3 red and 2 black ball. Another bag contains 4 red and 5 black balls. A ball is drawn from the first bag and is placed in the second. A ball is then drawn from the second. What is the probability that this draw of red ball is due to the drawing of red ball from the first bag ?
Options:
(A) 3/5
(B) 2/5
(C) 4/25
(D) 3/10
(E) 15/23
answer: Stream of consciousness: Probability of getting red ball from bag1 and then red from bag 2 = 3/5*5/10 = 15/50
Probability of getting black ball from bag1 and then red from bag 2 = 2/5*4/10 = 8/50
Now comes the condition, hence apply conditional probability:
P(Red)/ P(Red + Black)
(15/50)/(15/50+8/50) = 15/50 /23/50 = 15/23. The answer is (E).


q: How much is 80% of 45 is greater than 4/5 of 25?
Options:
(A) 15
(B) 57
(C) 16
(D) 16
(E) 73
a: Stream of consciousness: (80/100) * 45 â€“ (4/5) * 25
36 - 20 = 16 The answer is (C).


q: In what time will Rs.4000 lent at 3% per annum on simple interest earn as much interest as Rs.5000 will earn in 5 years at 4% per annum on simple interest?
Options:
(A) 5 years
(B) 6 years
(C) 7 years
(D) 9 years
(E) 15 years
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: (4000*T*5)/100 = (5000*5*4)/100
T = 5 years The answer is (A).