Question

3/28 of the animals are birds. 4/15 are birds of prey. What fraction of the animals are birds of prey.

Answer 1

let's call animals "a", and birds "b", birds of prey, "p"

so, b=$\frac{3}{28} a$

and p=$\frac{4}{15} b$
what;s the relation of p to a?

we substitude b into the last one:

and p=$\frac{4}{15}* \frac{3}{28} a$
so:
p=$\frac{4*3}{15*28} a$

p=$\frac{4*1}{5*28} a$


p=$\frac{1*1}{5*7} a$

p=$\frac{1*1}{35} a$

which is the answer!