Question

1/3 cup of flour is used to make 5 dinner rolls.

Answer 1

we know that

$\frac{1}{3}$ cup of flour is used to make $5$ dinner rolls.

Part a) How much flour is needed to make one dinner roll?

by using proportion

$\frac{\frac{1}{3}}{5} =\frac{x}{1} \\ \\ x=\frac{\frac{1}{3}}{5}\\ \\ x=\frac{1}{15}$

therefore

the answer Part a) is

To make one dinner roll is needed $\frac{1}{15}$ cup of flour

Part b) How many cups of flour are needed to make 3 dozen dinner rolls?

Multiply the value obtained in part a) by $36$

so

$\frac{1}{15} *36=\frac{36}{15} \\ \\ =\frac{12}{5}$

$\frac{12}{5} =2\frac{2}{5}$

therefore

the answer Part b) is

To make $3$ dozen dinner rolls are needed $2\frac{2}{5}$ cup of flour

Part c) How many rolls can you make with 5 2/3 cups of flour?

$5\frac{2}{3} =\frac{17}{3}$

by using proportion

$\frac{\frac{1}{3}}{5} =\frac{\frac{17}{3}}{x} \\ \\ \frac{x}{3} =\frac{85}{3} \\ \\ x=85$

therefore

the answer part c) is

$85$ rolls

Answer 2

A) 1/3 ÷ 5 = 1/3 x 1/5 (the reciprocal of 5)  or 1/15 cup to make a single dinner roll
B)  1/15 x 36 (3 dozen) = 36/15 2 $\frac{6}{15}$ cups or 2$\frac{2}{5}$ cups
C) 5 2/3 ÷ 1/15  = 17/3  x 15/1  = 225/3 = 85 rolls