Question

Alex who is sixteen years old is four times as old as her brother.how old alex be when he is twice old as her brother

Answer 1

HELLO DEAR,


GIVEN:-Present age of Mary is 16
Present age of her Brother is 4
(Since Mary is 4 times as old as him. 16/4 = 4)


now, when she is twice as old as her brother,


16 + x = 2(4 + x)

16 + x = 8 + 2x

8 = x

Add this value of 8 to Mary's & her brother's present age.

Mary's present age + 8 = 24
Her brother's present age + 8 = 12
(Mary is twice as old as her brother)


I HOPE ITS HELP YOU,
THANKS

Answer 2

Age of Alex = 16yrs old.

Age of brother = 1/4 times of Alex = 1/4 * 16 = 4 yrs.

Acc to the question, let us assume that after x years Alex would be twice old as his brother.

So, 2(4 + x) = (16 + x)

or, 8 + 2x = 16 + x

or, x = 8.

Age of Alex: 16 + 8 = 24.

Age of his brother: 4 + 8 = 12.

That means when Alex will be 24 years old then his brother will be 12 years old which is half the age.