Ques: If six persons sit in a row, then the probability that three particular persons are always together is -.
Options:
(A) 1/5
(B) 1/7
(C) 1/9
(D) 1/2
(E) 2/7
Ans: (A)
CoT: 3!4! Required probability = 3!4!/6! = 1/5

Ques: A light has a rating of 80 watts, it is replaced with a new light that has 25% higher wattage. How many watts does the new light have?
Options:
(A) 105
(B) 95
(C) 80
(D) 60
(E) 100
Ans: (E)
CoT: Final number = Initial number + 25%(original number) = 80 + 25%(80) = 80 + 20 = 100.

Ques: The average of 13 numbers is 59. Average of the first 7 of them is 57 and that of the last 7 is 61. Find the 8th number?
Options:
(A) 59
(B) 83
(C) 45
(D) 53
(E) 64
Ans: (A)
CoT: Sum of all the 13 numbers = 13 * 59 = 767
Sum of the first 7 of them = 7 * 57 = 399
Sum of the last 7 of them = 7 * 61 = 427
So, the 8th number = 427 + 399 - 767 = 59.

Ques: If a company allocates 10 percent of its budget to advertising, 10 percent to capital improvements, and 55 percent to salaries, what fraction of its budget remains for other allocations?
Options:
(A) 4/5
(B) 1/4
(C) 3/10
(D) 1/5
(E) 1/10
Ans: (B)

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
CoT: 10 + 10 + 55 = 75% 100 - 75 = 25% to all others