q: There are five same model cars parked in the same direction in parking. If 3 cars are red, 1 is black and 1 is green, in how many ways they can be arranged in the parking?
Options:
(A) 10 ways.
(B) 20 ways.
(C) 30 ways.
(D) 40 ways.
(E) 50 ways.
a: Stream of consciousness: 5!/(3!*1!*1!) = (5*4*3*2*1)/(3*2*1) = 120/6 = 20 ways. The answer is (B).
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q: A can do a work in 9 days and B can do the same work in 27 days. If they work together, in how many days will they complete the work?
Options:
(A) 6 3/4 days
(B) 7 3/4 days
(C) 5 3/4 days
(D) 6 1/4 days
(E) 6 2/4 days
a: Stream of consciousness: One day's work of A and B = 1/9 + 1/27 = (3+1)/27 = 4/27 So, the time taken to complete the work is 6 3/4 days. The answer is (A).
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q: If 85 percent of the test takers taking an old paper and pencil GMAT exam answered the first question on a given math section correctly, and 70 percent of the test takers answered the second question correctly, and 5 percent of the test takers answered neither question correctly, what percent answered both correctly?
Options:
(A) 60 %
(B) 65 %
(C) 70%
(D) 75%
(E) 80%
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: {Total} = {First correctly} + {Second correctly} - {Both correctly} + {Neither correctly}
100 = 85 + 70 - {Both correctly} + 5
{Both correctly} = 60. The answer is (A).
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