Question

Robyn adopted a child who is exactly 28 years younger than her.

In one year's time, Robyn will be 3 times as old as her child will be.
How old is Robyn now?

Answer 1

Robyn is 41years

Explanation:

let's represent Robyn age as x

so Robyn=x

child=x-28

In a year time

Robyn=x+1

child=x-28+1 =x-27

"Robyn will be three times as old as her child"

here multiply 3 by the child's age

child=3(x-27)

=3x-81

hence,x-1=3x-81. (group like terms)

x-3x=(-81-1)

-2x=-82 (divide both side by -2)

x=-82/-2

x=41

Therefore Robyn's age is 41

Answer 2

Robyn is 41

Explanation:

You want to know Robyn's current age if she will be 3 times as old as her 28-year younger daughter in one year from now.

Ratio units

The difference in ages remains constant. When Robyn is 3 times as old as her daughter, the ratio of their ages is ...

Robyn : daughter = 3 : 1

The difference in their ages is 3 -1 = 2 ratio units. Each ratio unit stands for 28/2 = 14 years, so Robyn's age of 3 ratio units represents 42 years.

That will be 1 year from now, so Robyn is 41.