To make a shelf to display her teapot collection, Amina bought wood and nails. Each yard of wood costs $27 and each box of nails
cost $4. She bought 6 fewer boxes of nails than yards of wood. Use this information for number 21 and 22. 21. Let x represent the number of yards of wood that Amina bought. Which expression could Amina use to represent the number of boxes of nails that she bought?
A. x
B. 4
C. x - 6
D. x + 6
22. Amina's total cost was $193. How many boxes of nails did she buy?
<span>Since the number of nail boxes is 6 less than the number of yards of wood, the right expression to use is x-6. (x being the number of yards of wood)
Now let us calculate the number of nail boxes she bought.
Cost of x yards of wood at $27 per yard = 27x.
Cost of x-6 boxes of nails at $4 per box = 4(x-6) = 4x - 24
Therefore 27x +4x - 24 = 193
31x -24 = 193
31x = 193 + 24
31x = 217
x = 217/31
= 7
So she bought 7 yards of wood and 7-6 boxes of nail. That is, she bought only one box of nail.</span>