Removing the Ends

At a diving competition, Jonathon’s first dive received seven scores that averaged (mean) 8.0. To calculate his final score for the dive, the highest and lowest scores were removed and the average (mean) was then taken of the five remaining scores. If his final score was 7.7, what was the sum of the two removed scores?

(Source: Adapted from Mathematics Teaching in the Middle School, Sep 1997)