HELP ASAP An office supply store sells pens and highlighters. In one month, 850 total pens and highlighters were
sold for a total revenue of $561. Pens cost $.50 each and highlighters cost $1.50 each. How many pens
and highlighters were sold?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of