Valley High School junior Arjun Ganga, son of Keka and Prabhakar Ganga of West Des Moines, earned a top composite score of 36 on the ACT, according to ACT Inc. It is the highest score possible on the college readiness exam. Only about one-tenth of 1 percent of students nationally receive a top score. With an average composite score of 22.2, Iowa has the second-highest average ACT composite score in the nation among states that test a majority of their graduating seniors. Ganga is the co-founder and co-director of the Des Moines Student-to-Student STEM Speaker Series, which provides students with monthly lectures given by STEM professionals.