The average of seven numbers is 24. The average of first three numbers is 14 and the average of last three numbers is 19. What is the middle number?
Options:
(A) 27
(B) 29
(C) 31
(D) 34
(E) 69
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The total of seven numbers = 7X24 = 168
The total of first 3 and last 3 numbers is = 3 X 14+3 X 19 = 99
So, the middle number is (168 - 99 ) = 69 So the answer is: (E).
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A can do a piece of work in 14 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 18
(B) 77
(C) 66
(D) 55
(E) 14
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8/14 + 6/x = 1
X = 14 days So the answer is: (E).
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What is the are of an equilateral triangle of side 8 cm?
Options:
(A) 645
(B) 649
(C) 163
(D) 643
(E) 642
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Area of an equilateral triangle = 3/4 S2
If S = 8, Area of triangle = 3/4 * 8 * 8 = 163 cm2; So the answer is: (C).
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