Question

solve the following ​

Answer 1

Step-by-step explanation:

let the unknown marks of the 6th subject be x

then,85+83+81+79+77+x/600=82.5/100

405+x=495

x=90

Answer 2

Let it be x

we know that,

Average = total sum of the no. / no of. items on a set.

➠ 82.5 = 85 + 83 + 81 + 79 + 77 + x/6

➠ 82.5 = 405 + x/6

➠ 82.5 × 6 = 405 + x/6

➠ 495 = 405 + x

➠ x = 495 - 405

➠ x = 90 ans.