In how many ways letters MMMPPPQRS can be arranged if Q need to be to the right of letter R?

An animal shelter has 21 puppies. if the puppies are 28% of the total dogs and cat population how many dogs and cats are in the animal shelter

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Apple pie is removed from 350 degree oven. temperature of the pie t minutes after being removed id given by the function t(t)=72+268e-0.068t