Simone wants to estimate the number of deer in a forest . She catches 60 deer and puts an orange mark on each one of them . She then releases them back into the forest . A week later she catches 30 deer and finds that 9 of them have an orange mark . Estimate the number of deer in the forest .
9/30 = 30% which had marks.
So, we assume that 60 = 30% of the total.