By turning a word question into algebra, we can solve it:
Q. There are twice as many sheep as cows in a field. How do we write this as an equation?
Let number of cows be C and the number of sheep be S.
There are twice as many sheep as cows, so S must be twice C.
We write this as S = 2C
Q. Jess is 4 years older than Matt. Their total age is 100. How old are they?
Let Jess be x years old, using a letter, because her age is unknown.
Jess is 4 years older than Matt. So Matt’s age is x – 4 years old.
Total age is x(Jess) + x – 4(Matt) = 100.
or 2x – 4 = 100; so 2x = 104; so x = 52.
So Jess is 52 and Matt is 48.
Q. Cyril, Jen and Brian combined age is 100.
Cyril is twice as old as Jen and she is 4 years older than Brian.
How old are they?