Explanation : x = 79 marks
The marks scored by Mike on four math test are 88,91,75 and 72.
Average of marks, A = 81
Let in fifth test he scores x marks.
The formula for finding average is :




In the fifth test he scores 79 marks.
Hence, this is the required solution.
D is the correct answer to this question. Here is a chart of energy transfer.
Dead things were once living, such as a dead plant. Non-living things were never alive, like coal.
Is this a true or false question?