Well since he packs rolls twice as fast as muffins we get

Does this make sense?? lets check

if he packs one muffin he would then have packed two rolls.

He packs crackers 2.5 times faster than rolls

Does this make sense? (yes)

Now we can use the above info to solve 250 crackers in one hr so we solve

now using r=100 in the 1st equation we get

so he can pack 50 muffins in one hour. yeah!!