When x is 3, y is 15. if y varies directly as x, which equation relates x and y?

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 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?

The tree filled 3/4 of a cup in 1/2 and hour at what rate does syurup flow from the tree

Aiko jumped rope for 20 min and stopped at 8: 05 when did she start