We can set up two equations
I’ll substitute Pamela for the variable P and Jiri for a variable J
Equation 1: J= P+13
Equation 2: P+J=61
I can substitute J in the second equation by what we found J to be equal in the first equation. So we get:
P+(P+13)=61
P+P+13=61
2P+13=61
2P=48
P=24 - so we now know that Pamela is 24 and we can use that to find Jiri’s age.
So let’s plug it in to our first equation of J=P+13
J=24+13
J=37 - so Jiri is 37 years old
