The total value of the coins in each row is shown in the yellow square at the end of the row. The total value of the coins in each column is shown in the yellow square at the bottom of the column. The total value of each diagonal is indicated by the 45 and the 65 in the yellow squares of the very top row.
Fill in the remaining coins necessary to make the totals come out right.
From Mensa Puzzle Calendar 2018 by Fraser Simpson, Workman Publishing, New York. Puzzle for September 5.