Answer:
Step-by-step explanation:
Keep in mind that to find the average they would do:
Average = Sum of students' ages / number of students
So to solve this question we should firstly find the sum of all their ages.
To do this you multiply 5 by 9 = 45.
This means 45 is the sum of all 5 students' ages.
Next you are given four students have ages 5 , 7 , 8 and 15.
The sum of their ages are: 5 + 7 + 8 + 15 = 35
This means that the final student has age 45 - 35 = 10 years.
