How much did he spend?

$6

Step-by-step explanation:

Glass beads cost $10 per pound

He didn't buy upto one pound, just 3/5

He spent $6

I think it would be because say you have a square and all the sides are 4. If you add all the sides you would get 16 for the perimeter. If you do 4 x 4 you would get 16 as the area. So i think they are the same but i am sometimes stupid so dont just take my word on it.
Hope this helps! :)