So first u add 1/4 to 1/4 to get how much each cat eats eats day and combine it:
1/4+1/4=1/2
So her cats eat 1/2 a tin of cat food every day.
Next we will try to find the unit rate:
1/2 • 2 = 1
So it takes her cats 2 days to eat 1 tin multiply 2 by 9 because 9 tins and 2 days for 1 tin
2 • 9 = 18
18 days for 9 tins of cat food is the answer