We know that Center 1 collects 715 pints per day and Center 2 collects 1035 pints per day.
They are asking for the estimated combined amount of blood from both centers in 3 days.
Estimate 715 as 700, and 1035 as 1000
This is written as
3(700+1000)= estimated total amount
To evaluate, simplify.
3(1700)= 5100 pints in 3 days from both centers
