There were 640 T-shirts at a shop. ³₈ of them were without collars. T-shirts without collars were priced at $10 each. T-shirts with collars were priced at $11 each. The shop owner sold ²₅ of the T-shirts without collars and ⁴₅ of the T-shirts with collars. How much did he collect from all the T-shirts he sold?
Number of T-shirts = 8 u

8 u = 640

1 u = 640 ÷ 8 = 80

Number of T-shirts without collars
= 3 u
= 3 x 80
= 240

Number of T-shirts without collars sold 
= ²₅ x 240
= 96

Number of T-shirts with collars
= 5 u
= 5 x 80
= 400

Number of T-shirts with collars sold
= ⁴₅ x 400
= 320

Amount that the shop owner collected from the sale of the T-shirts without collars
= 96 x 10
= $960

Amount that the shop owner collected from the sale of the T-shirts with collars
= 320 x 11
= $3520

Total amount that the shop owner collected from all the T-shirts he sold
= 960 + 3520
= $4480

Answer(s): $4480