SSC CHSL 10-Jan-2017 Shift 3 Paper

Three numbers a,b,c are in proportion iff b2=ac where b is the mean proportion and c is the third proportion Mean proportion of two numbers x and y = 6
⇒ xy=(6)2=36 -------(i)
Third proportion = 48
⇒ y2=x×48 ----(ii)
Substituting value of x from equation(i) in equation(ii), we get :
⇒ y2=

36

y

×48
⇒ y3=(2)3×(6)3=(12)3
⇒ y=(12)

3

3

=12
Substituting it in equation(i), ⇒ x=

36

12

=3