alanforde800Maximus wrote:

A T-shirt supplier charges $12 per T-shirt for the first 50 T-shirts in an order and $10 per T-shirt for each additional T-shirt in the order. If the charge for an order of T-shirts was $1500, how many T-shirts were in the order?

A) 90

B) 125

C) 140

D) 150

E) 200

The trap here is forgetting to account for or to "add back" the first 50

I. ArithmeticHow many T-shirts were there in an order charge of $1500?

Cost 1: $12 per T-shirt for first 50 = $600

Cost 2: $10 per T-shirt, for any number \(x\) T-shirts, AFTER the first 50

T-shirt order total: $1500

(1)

50 T-shirts cost $600

($1500 - $600) = $900 remain

(2) $900 = how many T-shirts?

$900/$10 per shirt =

90 shirts

Number of T-shirts in the order?

50 + 90 = 140

Answer C

II. AlgebraLet \(x\) = # of T-shirts

\((12)(50) + (10)(x-50) = 1500\)

\(600 + 10x - 500 = 1500\)

\(10x + 100 = 1500\)

\(10x = 1400\)

\(x = 140\)Answer C

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