Question

A recipe for a particular type of muffins requires 1 cup of milk and 1.5 cups of chocolates. Riya has 7.5 cups of chocolates. If she is using the recipe as a guide, how many cups of milk will she need to prepare muffins?


[3 marks]

Answer 1

A particular type of muffin requires $1$ cup of milk and $1.5$ cups of chocolates.​

Riya has $7.5$ cups of chocolates.
Let the number of cups of milk required be $x$ cups.

Cups of milk	$1$	$x$
Cups of chocolates	$1.5$	$7.5$

[0.5 mark]

As number of cups of chocolates are increased, the required number of cups of milk will also increase.
Hence, the number of cups of milk ($M$) and chocolates ($C$) is in direct proportion.
$\Rightarrow \frac{M}{C}=constant$
$\Rightarrow \frac{M_1}{C_1}=\frac{M_2}{C_2}$

[1 mark]

$\Rightarrow \frac{1}{1.5}=\frac{x}{7.5}$
$\Rightarrow x=\frac{1\times 7.5}{1.5}=5$ cups

Thus, the number of cups of milk required for $7.5$ cups of chocolate is $5$ cups.

[1.5 marks]