Question

There are 17 students in a class. On the day the test was given, John was absent. The other 16 students took the test, and their average score is 77. The next day John took the test, and with his grade included, the new average is 78. What is John's grade on the test?

Answer 1

Explanation:

Total scores of 16 students with an average score of 77= 16x77= 1232 scores.

The nextday scores of 17 students with an average scores of 78 John inclusive =77x78 = 1326.

Therefore, the grade of John in the test, = 1326 - 1232

= 94grades.

Answer 2

John got 94 marks

Explanation:

average = total numbers/ no. of students

77= x/16--------------1

78=x+y/17------------2

From 1 : x= 77*16= 1232--------------3

From 2: x+y= 78*17= 1326---------4

subtracting 3 from 4

y= 1326-1232= 94