what is 1/3 + 2/5

what you do is take the two bottom numbers and find their lowest common multiplier in the case of 3 and 5 its 15 

so to turn 3 into 15 you multiply it by 5 and you have to do the same to the top number so multiply 1 by 5 and you get 5

and 1/3 turns to 5/15

you do the same for 2/5 to get to 15 multipy 5 by 3 and then do the same for 2

and you get 6/15

then its 5/15  +   6/15 and when the bottom numbers are the same just add the top numbers  so 5+6=11

and then you get   11/15

Excellent answer anonymous!

Why don't you join up and then you could get proper credit!