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?
Step-by-step 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,
Since,
There are 36 black cards in the pile.
Then,
Hence, there are 9 red cards in the pile.