Q. If numbers N and K are added to set X {2, 8, 10, 12}, its mean will increase by 25%. What is the value of N^2 + 2NK + K^2 ?
(A) 28 (B) 32 (C) 64 (D) 784 (E) 3600
IMO D, am I correct?
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MBA.Aspirant
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MI3 wrote:Q. If numbers N and K are added to set X {2, 8, 10, 12}, its mean will increase by 25%. What is the value of N^2 + 2NK + K^2 ?
(A) 28 (B) 32 (C) 64 (D) 784 (E) 3600
IMO D, am I correct?
mean = 32/4 = 8
mean ^ 25% = 10
sum = 10*6 = 60
n+k = 60 -32 = 28
n^2 +2nk +k^2 = (n+k) (n+k) = 28 * 28 = 784
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amit2k9
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(N+K + 32)/6 = 8*1.25 = 10
thus N+K = 60-32 = 28
hence (N+K)^2 = 784
thus N+K = 60-32 = 28
hence (N+K)^2 = 784
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