All 23 of mr. rodman's students visited the school store. 17 students bought pencils. 12 students bough paper. how many students bought both pencils and paper?

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Math it's appreciated. (picture provided)

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?