PLZ HELP: Two senior customer service representatives (CSPs) and 8 junior CSRs work for IvyTech. Last week, the senior CSRs each helped 4 more custoomers than the average number of customers helped per junior CSR. If IvyTech's CSRs helped 138 customers last week, how many of those customers were helped by senior CSRs? A. 17 B. 26 C. 34 D. 42 PLZ EXPLAIN