What are the unknowns in this problem?

a problem states: "there are 9 more pencils than pens in a container. there are 25 writing utensils in the container in all. how many pens are there in the container? "

select each correct answer.

the total number of pens in the container in all

the total number of writing utensils in the container in all

the total number of pencils in the container in all

the total number of markers in the container in all

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?

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.

Suppose you just purchased a digital music player and have put 8 tracks on it. after listening to them you decide that you like 4 of the songs. with the random feature on your player, each of the 8 songs is played once in random order. find the probability that among the first two songs played (a) you like both of them. would this be unusual? (b) you like neither of them. (c) you like exactly one of them. (d) redo () if a song can be replayed before all 8 songs are played.