Question 196867
Steve is three times as old as Theresa. In four years he will be twice as old as she will be. How old is each now?
:
Let s = Steve's age now
Let t = Teresa's age now
:
Write an equation for each statement:
"Steve is three times as old as Teresa."
s = 3t
:
"In four years he will be twice as old as she will be."
s + 4 = 2(t+4)
s + 4 = 2t + 8
s = 2t + 8 - 4
s = 2t + 4
Substitute 3t for s and find t
3t = 2t + 4
3t - 2t = 4
t = 4 yrs is Teresa's age
then
s = 3(4)
s = 12 yrs is Steve's age
:
Check solution in the statement
"In four years he will be twice as old as she will be."
12 + 4 = 2(4 +4)