Gary began peeling a pile of 44 potatoes at the rate of 3 per minute. 4 minutes later, christen joined him, and peeled at the rate of 5 potatoes per minute. when they were finished, how many had each peeled?

Ok, so 3 per minute for 4 minutes is 3x4=12, so Gary peels 12 to start with. That leaves us with 44-12=32 potatoes. 1 minute later, Gary has peeled 3 more (12+3=15 in total) and Christen has peeled 5. There are now 32-3-5=24 left. Another minute, and Gary peels 3 more (15+3=18 in total) and Christen has peeled 5 more (5+5=10 in total). There are now 24-3-5= 16 left. Another minute, and Gary has peeled 3 more (18+3=21 in total) and Christen has peeled 5 more (10+5=15 in total). There are now 16-3-5=8 left. another minute, and Gary has peeled 3 more (so now he has done 21+3=24 in total). Christen has done 5 more (15+5=20 in total) and there are now 8-3-5=0 potatoes left. So now all the potatoes have gone, Christen has peeled 20, and Gary has peeled 24. Hope that makes sense :)