The present average age of a couple and their daughter is 35 years. Fifteen years from now, the age of the mother will be equal to the sum of present ages of the father and the daughter. Find the present age of mother?
43 years
40 years
48 years
45 years
Explanation:
let the sum of the daughter's and the father's age be 'x'
let the mother's age be 'y'
therefore their average age = x+y= 35
therefore, x + y= 105 ----(1)
now, 15+y=x
therefore x-y = 15-----------(2)
adding 2 and 1 we get
so, x+y=105
x-y =15
__________________
2x=120
therefore x=60
putting x=60 in equation (1)when we get,
y=105-60
y=45
so the Ans is 45
let the sum of the daughter's and the father's age be 'x'
let the mother's age be 'y'
therefore their average age = x+y= 35
therefore, x + y= 105 ----(1)
now, 15+y=x
therefore x-y = 15-----------(2)
adding 2 and 1 we get
so, x+y=105
x-y =15
__________________
2x=120
therefore x=60
putting x=60 in equation (1)when we get,
y=105-60
y=45
so the Ans is 45