Remark
The trick here is to realize that you have to find the number both have in order to find the difference. That means you take (effectively) 3/8 and 5/8 to find out how much each of them has. The 8 stands for the 136
Step One
Find the number of stamps Alex has. Remember his ratio is the smaller so he will have 3/8
Alex = 3/8 * 136
Alex = 408/8 = 51
Step 2
Find the number that Freddy has.
The total is 136
Formula
Freddy = Total - Alex
Freddy = 136 - 51
Freddy = 85
Check
Let us see if 5/8 * 136 = 85
5*136/8 = 680 / 8 = 85 So your answers are correct.
Difference
Difference = 85 - 51 = 34 which is how many more stamps Freddy has than Alex.
