To meet a government requirement, a bottler must test 5 percent of its spring water and 10 percent f its sparkling water for purity if a customer ordered 120 cases of spring water and 80 cases of sparkling water, then what percent of all the cases must the bottler test before he can send it out? `6. 5 %` b. `7. 0 %` c. `7.5 %` d. 8.0%