Question

a chocolate chips cookie recipe asks for one and two quarters tines as much flour as chocolate chips. if two and one half cups of flour is used what quantity of chocolate chips would then be needed according to the recipe

Answer 1

For every portion of chocolate chips, 1.5 (one and two quarters) portions of flour are needed. Let x denotes the number of cups of chocolate chips needed when 2.5 (two and one half) cups of flour are used. The next proportion must be satisfied:

$\frac{1\text{ cup of chocolate}}{x\text{ cup of chocolate}}=\frac{1.5\text{ cups of flour}}{2.5\text{ cups of flour}}$

Solving for x:

$\begin{gathered} 1\cdot2.5=1.5\cdot x \\ \frac{2.5}{1.5}=x \\ 1\frac{2}{3}=x \end{gathered}$

One and two-thirds cups of chocolate chips are needed