Question

There are 600 counters in a bag 90 of them are yellow.

Answer 1

3 over 20 is the fraction in simplest form.

Answer 2

90 of the 600 are yellow
that is
90/600 are yellow
greatest common factor is 30
so 90/30 = 3
and 600 /30 = 20
so the fraction simplified is
3/20 counters are yellow

Hope this helps :)