Reasoning: P1 takes 12 hrs
Rate for P2P3 together = 1/20 + 1/20 = 1/10
Therefore they take 10
Ratio = 10/1 =
Ans: (D)
Question: Working alone, Printers X, Y, and Z can do a certain printing job, consisting of a large number of pages, in 12, 20, and 20 hours, respectively. What is the ratio of the time it takes Printer X to do the job, working alone at its rate, to the time it takes Printers Y and Z to do the job, working together at their individual rates?
Options:
(A) 4/11
(B) 1/2
(C) 15/22
(D) 10/1
(E) 11/4
Rationale: Left After 1st stroke = 1/2
Left After 2nd stroke = 1/2 * 1/2 = 1/4
Left After 3rd stroke = 1/2 * 1/4 = 1/8
Left After 4th stroke = 1/2 * 1/8 = 1/16
Left After 5th stroke = 1/2 * 1/16 = 1/32
Left After 6th stroke = 1/2 * 1/32 = 1/64
So removed = 1- 1/64 = 63/64
The answer: (A)
Question: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 6 strokes ?
Options:
(A) 63/64
(B) 7/8
(C) 1/4
(D) 1/8
(E) 1/16
Reasoning: 1 also gives the remainder of 1 when divided by 3. So, there are total of 20 numbers.
Ans: (E)
Question: How many positive integers less than 60 have a reminder 01 when divided by 3?
Options:
(A) 13
(B) 14
(C) 15
(D) 16
(E) 20
Rationale: 5 people can be prized with 3 distinct prizes in 5^3 ways
The answer: (A)
Question: In a race with 30 runners where 3 trophies will be given to the top 5 runners (the trophies are distinct: first place, second place, etc), how many ways can this be done?
Options:
(A) 5^3 ways
(B) 8^9 ways
(C) 7^8 ways
(D) 8^7 ways
(E) 8^6 ways
Reasoning: Place D and H first: 8 options for D, 7 options for H
We are left with 6 empty places. A, B and C must take first 3 places and F, G, Emust take the remaining three. A, B and C can be arranged in their places in 3! ways. The same for F, G, and E
Total = 8*7*3!*3! = 2*1008
Ans: (D)
Question: In how many different orders can the people Alice, Benjamin, Charlene, David, Elaine, Frederick, Gale, and Harold be standing on line if each of Alice, Benjamin, Charlene must be on the line before each of Frederick, Gale, and Elaine?
Options:
(A) 1,008
(B) 1,296
(C) 1,512
(D) 2*1008
(E) 2,268
Reasoning: 2nd day he earns = 3(2 3)
3rd day he earns = 3(3 3)
On 15th day he earns 3(15 -3) = 36 rupees
Ans: (E)
Question: An seller earns an income of Re 3 on the first day of his business. On every subsequent day, he earns an income which is just thrice of that made on the previous day. On the 15th day of business, he earns an income of:
Options:
(A) 19
(B) 22
(C) 25
(D) 20
(E) 36