QUESTION $3$

An ammonia process system has supply tanks containing $64,980lbs.$ of nitrogen and $20,000lbs.$ of hydrogen. The tanks will be refilled in $36$ hours and there must be a $2,020$ poud reserve of nitrogen and a $920$ pound reserve of hydrogen. What is the maximum rate at which the supply of hydrogen can be used per hour?

$1,750lbs\frac{.}{h}r.$

$556lbs\frac{.}{h}r.$

$530lbs\frac{.}{h}r$

$1,805lbs.hr.$