sam can solve 30 multiplication problems in 2 minutes how many can he solve in 20 minutesl
take 30 * 10 to find out how many problems same can figure out. That is how you got from 2 to 20 is multiplying by 10
30 problems = 2 minutes
300 problems = 20 minutes
300 because if he can do 30 in 2 min. then 300 cause u are adding a zero to 2.