Question

A man is 50 year has 8 son born of equal inteval.the sum of the ages is 186.what is age of the eldest if youngest is 3 year old

Answer 1

given age of man=50
he has 8sons
mean age of sons =22year
so according to problem

50+total age of sons=50+8/2(young +older]=186

50+8/2(young +older]=186
50+4(3+elder son)=186
50+12+4e=186
4 e=186-62
e =124/4
e=31 years

therefore age of eldest son is 31years

Answer 2

Let the interval between the birth of children = x
Ages of the children = 3, 3+x, 3+2x, 3+3x, 3+4x, 3+5x, 3+6x, 3+7x
A/Q 50+3+(3+x)+(3+2x)+(3+3x)+(3+4x)+(3+5x)+(3+6x)+(3+7x) = 186
74+28x = 186
28x = 112
x = 4
∴ The age of eldest son = 3+7x = 3+28 = 31 years