Answer: Cost per pair of jeans = $ 20
Cost per pair of shorts = $12
Cost per shirt = $8
Step-by-step explanation:
Let x= cost per pair of jeans
y = Cost per pair of shorts
z= cost per shirt.
For you, total cost = x+4y+2z= 84
For your friend, total cost = 2x+y+3z=76
For cousin, total cost = x+2y+z= 52
Required system:

from (i),
(*)
put this in (ii) and (iii) we get

from (iv), 






Hence, x= 20, y= 12 , z=8
So, Cost per pair of jeans = $ 20
Cost per pair of shorts = $12
Cost per shirt = $8