If bacteria took 20 minutes to double from 2 to 4, how many bacteria would there be after 1 hour

Easy points boii. read it. ya. fresh

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?

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?