Ryan got 80% of the problems on a 25-problem test, 90% on a 40-problem test, and 70% on a 10-problem test. What percent of all problems did Ryan answer correctly? <spanclass=′latex−bold′>(A)</span>64<spanclass=′latex−bold′>(B)</span>75<spanclass=′latex−bold′>(C)</span>80<spanclass=′latex−bold′>(D)</span>84<spanclass=′latex−bold′>(E)</span>86