Question

Perry live s 3.7 mi north of school. Jerry lives 2.5 mi south of school. Terry lives 1.4 mi south of Perry. How far is it from Terry's house to Jerry's house?

Answer 1

4.8 miles

Explanation:

All the "...erry" names get confusing - I'll use P, J, and T.

Let's think of this in this way:

We know that P lives to the north of the school - he walks 3.7 miles to get to school.

We also know that J lives 2.5 miles south of the school. And so if P walks to J's house, he walks 3.7 miles to school and then another 2.5 miles to J's house, a total of `2.5+3.7=6.2` miles.

Lastly, we're told that T lives 1.4 miles south of P. And so for P, he can walk 1.4 miles to T, another 2.3 miles to school `(=3.7-1.4=2.3)` and then another 2.5 miles to J's house.

So what about T and walking to J's house?

We just figured out that when P walks to school, once he reaches T's house, he has another 2.3 miles to go to get to school, and so T also walks 2.3 miles to school. He can then walk another 2.5 miles to J's house, for a total of `2.3+2.5=4.8` miles.

We can express all this in a single expression:

`(3.7-1.4)+2.5=2.3+2.5=4.8` miles