Question

Laura is baking a cake. The recipe says that she has to mix 64 grams of chocolate powder into the flour. Laura knows that 1 cup of that particular chocolate powder has a mass of 128 grams. She added two over three of a cup of chocolate powder to the flour. Should Laura add more chocolate powder to make the exact recipe, or did she go over and by what amount?

She went over by one over three of a cup.
She needs to add one over three of a cup.
She needs to add one over six of a cup.
She went over by one over six of a cup.

Answer 1

`1\ cup=128\ grams \\ \\ { (2)/(3) }\ cups= 128* { (2)/(3) } \\ \\ = 85{ (1)/(3) }\ grams \\ \\ \\ \\ 85{ (1)/(3) }-64= 21{ (1)/(3) }\ grams \\ \\ { \cfrac{21{ (1)/(3) }\ grams}{128\ grams} }={ (1)/(6) }\ cups. \\ \\ \\ \\ She\ went\ over\ by\ one\ over\ six\ of\ a\ cup.`