• Sep 11th 2009, 12:58 PM
cnotez
Sarah needs to make a cake and some cookies. The cake requires 3/8 cup of sugar and the cookies require 3/5 cup of sugar. Sarah has 15/16 cups of sugar. Does she have enough sugar, or how much more does she need?
A. She has enough sugar.
B. She needs 1/8 of a cup of sugar.
C. She needs 3/80 of a cup of sugar.
D. She needs 4/19 of a cup of sugar.
E. She needs 1/9 of a cup of sugar.
• Sep 11th 2009, 01:27 PM
pickslides
She needs $\frac{3}{8}+\frac{3}{5} = \frac{3\times 5}{40}+\frac{3\times 8}{40}= \frac{15}{40}+\frac{24}{40} = \frac{15+24}{40}= \frac{39}{40}$ cups of sugar

She has $\frac{15}{16}$ cups of sugar

as $\frac{39}{40} > \frac{15}{16}$

she requires $\frac{39}{40} - \frac{15}{16}$ cups of sugar

can you solve it?
• Sep 11th 2009, 06:00 PM
cnotez
Thank you. I can solve it now.