Question

Suppose that Sahil knows that 45 people with ages of 18 to 29 voted. Without using a calculator, he quickly says then 135 people with ages of 30 to 49 voted. Is he correct? how might Sahil have come up with his answer so quickly?

Answer 1

His answer is correct because if you have the pie chart, it shows the percentage. he did 45 times 3 to get the 135 because he though since 10% is 45 people he could multiply by 3 & get his answer. 
Hope this helped.