let the number of birds be x and that of cats be y
The total number of animals will be:
x+y=46
⇒x=46-y
The total amount required for the caring will be:
x+6.5y=161.50
susbstituing the value of x in the above equation we get:
46-y+6.5y=161.50
solving for y we get:
5.5y=115.5
y=115.5/5.5
y=21
hence the number of cats is 21 cats, that of birds will be:
46-21=25 birds