Abby scored a 78 on her first test and a 54 on her second. If Abby needs a test average of 55 to pass the course, what is the lowest score that she can make on her third and final test and still pass?
The lowest average of the 3 tests must be 55 in order for Abby to pass.
Let the lowest mark be
The high mark in the first test means that she only needs 33 in the third test to have an average of