Answer:
A) 3
Step-by-step explanation:
If you simply look at the given numbers, it should be pretty clear that 3 tenths is 3 times 1 tenth.
When Mary puts 1/10 kg in each cage, she can do that for 3 cages with 3/10 kg of bird seed.
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If you let c represent the number of cages, then the amount of bird seed used will be (1/10)c. This will be equal to the amount available when we use it all for filling cages:
(1/10)c = (3/10)
Multiply both sides of the equation by 10:
c = 3
Mary can fill 3 cages with available seed.
