gmat1393
3 teaspoons = 1 tablespoon
4 tablespoons = 1/4 cup
According to the information above, how many teaspoons are equal to 3/8 cup?
A. 3
B. 4
C. 9
D. 12
E. 18
\(3\,\,{\text{teaspoons}}\,\,\,\, \leftrightarrow \,\,\,\,1\,\,\,{\text{tablespoon}}\)
\(4\,\,{\text{tablespoons}}\,\,\,\, \leftrightarrow \,\,\,\,\frac{1}{4}\,\,\,{\text{cup}}\,\,\,\,\,\)
\(\frac{3}{8}cup\,\,\, = \,\,\,\,?\,\,\,{\text{teaspoons}}\)
\(\frac{3}{8}cup\,\,\,\left( {\frac{{4\,\,{\text{tablespoons}}}}{{\frac{1}{4}\,\,\,{\text{cup}}}}\,\,\begin{array}{*{20}{c}}\\
\nearrow \\ \\
\nearrow \\
\end{array}} \right)\,\,\,\,\left( {\frac{{3\,\,{\text{teaspoons}}}}{{1\,\,\,{\text{tablespoon}}}}\,\,\begin{array}{*{20}{c}}\\
\nearrow \\ \\
\nearrow \\
\end{array}} \right)\,\,\,\, = \,\,\,\frac{{3 \cdot 4 \cdot 4 \cdot 3}}{{8 \cdot 1}} = 18\,\,\,\,\,\,\,\,\,\left[ {{\text{teaspoons}}} \right]\)
This is a nice example of UNITS CONTROL technique, one of our most powerful tools!
(Arrows indicate
licit converters.)
The above follows the notations and rationale taught in the GMATH method.