# Lydia rode 243 miles in a three-day bike trip. On the first day, Lydia rode 67 miles. On the second day, she rode 92 miles. How many miles per hour did she average on the third day if she rode for 7 hours?

$12$ miles/hour
On the third day she rode $243 - 67 - 92 = 84$ miles
So per hour she averaged $\frac{84}{7} = 12$ miles/hour