Question

An animal shelter spends $3.50 per day to care for each bird and $6.50 per day to care for each cat. Brooklyn noticed that the shelter spent $146.50 caring for birds and cats on Friday. Brooklyn found a record showing that there were a total of 29 birds and cats on Friday. How many birds were at the shelter on Friday?

Answer 1

Solution: Let $x$ be the number of birds and $y$ be the number  of cats.

$x+y=29 \implies y=29-x$

$3.50 x +6.50 y= 146.50$

$3.50 x+6.50(29-x)=146.50$

$3.50x+188.5-6.5x=146.50$

$3x=188.5-146.50$

$3x=42$

$x=\frac{42}{3} =14$

Therefore, there were 14 birds at the shelter on Friday