Question

Karen is 21 years older now than Oliver. In 4 years Karen will be double Oliver’s age. How old is each now ?

Answer 1

Let

x -----> Karen's age now

y ----> Oliver's age now

we have that

x=y+21 --------> equation 1

(x+4)=2(y+4) ---> equation 2

Solve the system of equations

Substitute equation 1 in equation 2

(y+21+4)=2(y+4)

solve for y

y+25=2y+8

2y-y=25-8

y=17

Find out the value of x

x=17+21

x=38

therefore

Karen is 38 years old now

Oliver is 17 years old now