Answer:
The number of $1 bills are 7 and $5 bills are 8.
Solution:
Given, A student has $1 bills and $5 bills in his wallet.
He had a total of 15 bills that are worth $47.
We have to find how many of each type does he have?
Let the number of $1 bills be n then number of $5 bills be 15 – n.
And, according to given information, $1 x n + $5 x (15 – n) = $47
n + 5 x 15 – 5n = 47
n – 5n = 47 – 75
-4n = -28
4n = 28
n = 7
Then, number of $5 bills = 15 – 7 = 8.
Hence, the number of $1 bills are 7 and $5 bills are 8.