Can you solve these two problems on averages?

1.The class average in 10 tests was 72. Fatboy's average was 12 above the class average and Fatgirl's average was 8 below the class average.
Find the difference between Fatboy's and Fatgirl's total marks?

2. The difference between Shana's and Djuana's average in 7 tests is 15.If Djuanna had a score of 420 marks and Shana's total is higher, find Shana's score/