Mary, who is 16 years old, is 4 times as old as her brother. how old will mary be when she is twice as old as her brother

Mary will be 24 years old when she will be twice as old as her brother.

Here's how this has been calculated:

If Mary is 16 years old and 4 times older than her brother, her brother's age

= 16/4

=4

Mary’s brother is therefore 4 years old.

Now let’s calculate the difference between Mary and her brother’s age through subtraction:

Mary’s age - her brother’s age = 16-4

=12

Therefore, Mary is 12 years older than her brother

So, for Mary to be twice as old as her brother, the formula will be = 12*2

=24

Therefore, Mary will be 24 years old when she will be twice as old as her brother.