In a parking lot, some cars have 1 spare tire and others have no spare tires. all together, there are 43 tires and 9 cars. how many cares have a spare tire?

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

What are the digits that repeat in the smallest sequence of repeating digits in the decimal equivalent of 24/11?

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?