Question

Mary is making some shirts for her school's drama department. The fabric store has 3 1/6 yards of the fabric she wants in stock. But this quantity of fabric can make only 1 1/3 shirts. What length of fabric does Mary need to buy if she wants to sew 2 shirts?
A)1 1/6
B)2 3/8
c)3 5/6
D)4 3/4

Answer 1

Solve this problem using an equation of ratios.

3 1/6 yards of the fabric she wants in stock. But this quantity of fabric can make only 1 1/3 shirts

Write the ratio

3 1/6 yards to 1 1/3 shirts:

19
---
 6 
---------------
4
---
 3

We need to reduce this.  The first (upper) ratio is 19/6; the second (lower() ratio is 4/3.  We can mult. numerator and denom. of 4/3 both by 2 to obtain the equivalent ratio 8/6.

Then we have the ratio

19/6
--------  which can be reduced to 19/8.  That's  (19/8) yard/shirt.  We can use
8/6       this as a conversion factor.

To make 2 shirts, Mary will need  (19/8 yards per shirt)(2 shirts) of material, or 38/8 yards, or 19/4 yards (answer).