Jacks mother gave him 50 chocolates to give to his friends at his birthday party. he gave 3 chocalates to each of his friends and still had 2 chocalates left

What is 20+(5 x 2/5 )+ 3 show your work

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?

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?