Number of large and small boxes

Question

A contractor needs to buy nails to build a house, the nails come and small boxes and large boxes each small box has 150 nails in each large box has 400 nails the contractor about twice as many large boxes are small boxes which all together had 2850 nails determine the number of small boxes purchased in the number of large boxes purchased

Answer 1

150s +400L= 2850

L=2s

150s +400(2s)= 2850

950s =2850

s= 285/95= 3 small boxes

L=6 Large boxes