Reasoning: P(B|A) = P(A B)/P(A)
P(B|A) = (12/15)/(2/15) = 6.
Ans: (E)
Question: If P(A) = 2/15, P(B) = 4/15, and P(A B) = 12/15 Find P(B|A)
Options:
(A) 1/2
(B) 2/3
(C) 3/2
(D) 4/5
(E) 6
Rationale: 1/3: 1/2: 1/1 = 2:3:6
The answer: (D)
Question: The inverse ratio of 3: 2: 1 is?
Options:
(A) 2:9:5
(B) 2:3:0
(C) 2:3:5
(D) 2:3:6
(E) 2:3:1
Reasoning: Let 4300731 - ! = 2535618
Then !, = 4300731 - 2535618 = 1765113
Ans: (E)
Question: (4300731)-! = 2535618. Find value of !?
Options:
(A) 1213441
(B) 2354546
(C) 4354556
(D) 2435454
(E) 1765113
Rationale: B's 1 day work = (1/12 - 1/20) = 1/30
Now, (A + B)'s 1 day work = (1/20 + 1/60) = 1/15
So, A and B together will complete the work in 15 days.
The answer: (C)
Question: A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
Options:
(A) 65 days
(B) 85 days
(C) 15 days
(D) 45 days
(E) 13 days
Reasoning: In this simple alternating subtraction and addition series; The first series begins with 5 and adds 2; the second begins with 15 and subtracts 3, and so on.
Ans: (B)
Question: Fill in the blank with the correct number in this number series: 5, 15, 7, 12, __, 9, 11,... ?
Options:
(A) 6
(B) 9
(C) 8
(D) 7
(E) 5
Reasoning: Answer = C) Three
Two digit Numbers giving remainder 5 when divided by 10 = 15, 25, 35, 45, 55, 65, 75, 85, 95
The numbers giving remainder 0 when divided by 3 = 15, 45, 75 = 3
Ans: (C)
Question: Count the two-digit whole numbers which yield a remainder of 5 when divided by 10 and also yield a remainder of 0 when divided by 3?
Options:
(A) Two
(B) Five
(C) Three
(D) One
(E) Six