Eric and his work crew have 50 trees o plant. in 8 hours today, they planted 40 trees. if the work at the same rate tomorrow, how long will it take to finish planting the trees?

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