Let the present age of brother = x
and the present age of sister = y
according to the first condition
x + y = 16
or x = 16 - y .......(i)
according to the second condition
xy = 63.........(ii)
solving the equation (i) & (ii), we have,
(16 - y)y = 63
or, 16y - y^2 = 63
or, y^2 - 16y+63 = O
or, y^2 -9y - 6y + 63 = o
or, (y-9)(Y-7) = 0
or, (y - 9) = o
or, y = 9
put the value y in equation (i), we get
x =16 - 9
= 7
so, present age of brother = x = 7 years
and the present age of sister = y = 9 years
