Question 20
Four numbers $A,B,C,D$ are written in a row. The average of A and B is 70, the average of B and C is 23, and the average of C and D is 8. Find the average of A and D.
Source-key note: the printed short key conflicts with the stated averages. Solve using the averages as printed; the solution explains the discrepancy.
Source-key note: the printed short key conflicts with the stated averages. Solve using the averages as printed; the solution explains the discrepancy.