Average of five numbers is 61. If the average of first and third number is 69 and the average of second and fourth number is 69, what is the fifth number ?
Let the five numbers be a, b, c, d, e in the given order.
a+b+c+d+e = 61*5=305 ----- Eq 1
a+c = 69*2 = 138
b+d = 69*2 = 138
From eq 1: e=305-(138+138) =305-276 =29
B is the correct answer.
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