Let D be the number of stickers Dan has and C be the number of stickers Cam has D=2C D-15=C+15+22(because Dan will still have 22 more stickers after he gives Cam 15 of his, meaning Cam gains 15, Dan looses 15) Thus D-15=C+37, D=52+C Since D=2C, 2C=52+C Thus Cam has 52 stickers and Dan has 104 stickers(because D=2C=2(52))