Question

Question 3 options: The number of black cards in a pile is 4 times the number of red cards. There are 36 black cards in the pile. How many red cards are there? Let r represent the number of red cards in the pile.

Answer 1

Given

The number of black cards in a pile is 4 times the number of red cards.

There are 36 black cards in the pile.

To find:

How many red cards are there?

Explanation:

It is given that,

The number of black cards in a pile is 4 times the number of red cards.

There are 36 black cards in the pile.

That implies,

Let r represent the number of red cards in the pile.

Then,

$\begin{gathered} Number\text{ }of\text{ }black\text{ }cards=4\times Number\text{ }of\text{ }red\text{ }cards \\ =4r \end{gathered}$

Since,

There are 36 black cards in the pile.

Then,

$\begin{gathered} 4r=36 \\ r=\frac{36}{4} \\ r=9 \end{gathered}$

Hence, there are 9 red cards in the pile.