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Question

A contractor needs to buy nails to build a house. The nails come in small boxes and large boxes. Each small box has 50 nails and each large box has 400 nails. The contractor bought 3 times as many large boxes as small boxes, which altogether had 2500 nails. Determine the number of small boxes purchased and the number of large boxes purchased.

Answer 1

L = 3S

L-3S = 0

multiply by 400

400L - 1200S = 0

400L + 50S = 2500 nails

400L-1200S = 0

subtract to eliminate one variable, to get

1250S = 2500

S =2500/1250 = 2 small boxes

L = 3(2) = 6 large boxes

400(6) + 50(2) = 2400+100 = 2500 nails