Answer:
Let x be the variable for a t-shirt for $8. 
Let y be the variable for shorts for $12. 
Let z be the variable for the hats that cost $10 each. 
 
 
We have the expression 1 below: 
$464 = $8x + $12y + $10z 
other expressions: 
3z = x 
2z =y 
 
By substitution we can solve each variable: 
 
464 = 8(3z) + 12(2z) + 10z 
464 = 24z +24z +10z 
464 = 58z 
z = 8 
 
Solve for x andy: 
3z=x 
3*8 = 24=x 
2z=y 
2*8 = 16 = y 
 
The t-shirts are 24 pieces, the shorts are 16 pieces and hats are 8 pieces.
Explanation: