2.50 + 0.85p = 28.85 <== ur equation
0.85p = 28.85 - 2.50
0.85p = 26.35
p = 26.35/0.85
p = 31......so they gifts weighed 31 lbs
3 times the sum of a number and 5 times the number is 36...
3(n + 5n) = 36
3(6n) = 36
18n = 36
n = 36/18
n = 2........I am not 100% sure on this one