There were 280 T-shirts at a stall. ³₇ of them were without collars. T-shirts without collars were priced at $8 each. T-shirts with collars were priced at $11 each. The stall owner sold ¹₂ of the T-shirts without collars and ⁷₁₀ of the T-shirts with collars. How much did he collect from all the T-shirts he sold?
Number of T-shirts = 7 u

7 u = 280

1 u = 280 ÷ 7 = 40

Number of T-shirts without collars
= 3 u
= 3 x 40
= 120

Number of T-shirts without collars sold 
= ¹₂ x 120
= 60

Number of T-shirts with collars
= 4 u
= 4 x 40
= 160

Number of T-shirts with collars sold
= ⁷₁₀ x 160
= 112

Amount that the stall owner collected from the sale of the T-shirts without collars
= 60 x 8
= $480

Amount that the stall owner collected from the sale of the T-shirts with collars
= 112 x 11
= $1232

Total amount that the stall owner collected from all the T-shirts he sold
= 480 + 1232
= $1712

Answer(s): $1712