Question

5 years ago, Lanny is 4 times as old as Sarah. She is thrice as old as Sarah now. How many years younger is Sarah than Lanny

Answer 1

Answer:

Sarah is 30 years younger than Lanny.

Step-by-step explanation:

Let Lanny's present age be x

Let Sarah's present age be y

5 years ago, Lanny's age =x-5

equation 1 :x-5=4[y-5]

x-5=4y-20

x-4y=-15

equation 2: x=3y

substitute equation 2 into equation 1

3y-4y=-15

-y=-15

y=15

x=3(15)

x=45

x-y

=45-15=30

Sarah is 30 years younger than Lanny.