The average amount with a group of seven numbers is Rs. 20. If the newly joined member has Rs. 50 with him, what was the average amount with the group before his joining the group?
Options:
(A) Rs.17
(B) Rs.76
(C) Rs.15
(D) Rs.72
(E) Rs.71
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Total members in the group = 7
Average amount = Rs. 20
Total amount with them = 7 * 20 = Rs. 140
One number has Rs. 50. So, the amount with remaining 6 people = 140 - 50 = Rs. 90
The average amount with them = 90/6 = Rs. 15. So the answer is: (C).
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The measure of the side of a square is quadrupled. If x represents the perimeter of the original square, what is the value of the new perimeter?
Options:
(A) 3x
(B) 4x
(C) 9x
(D) 12x
(E) 27x
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Original perimeter = x
Hence original side = x/4
New side = 4x/4
New perimeter = 4*4x/4 = 4x So the answer is: (B).
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At a meeting of the 9 Joint Chiefs of Staff, the Chief of Naval Operations does not want to sit next to the Chief of the National Guard Bureau. How many ways can the 9 Chiefs of Staff be seated around a circular table?
Options:
(A) 120
(B) 480
(C) 960
(D) 2520
(E) 6050
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Bunuel, I'm also a little confused with the number of arrangements of n distinct objects in a circle. Why is it given by (n-1)!. In theveritasanswer they say:answer E (6050), should be the number of ways to arrange all 7 without the seating restriction given. Is this incorrect? So the answer is: (E).
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