Help with a math question for the school Final marks

Question

We Have 3 marks ok

The first mark is 89.8
and it = 35% from the Final mark

The second mark is 95.8

and it = 20% from the Final mark

The third mark is unknown

and it = 45% From the Final mark

Final Mark is = 90

I need to know the third mark, Note' is shoud be higher then 90 and maximum 100

Answer 1

The final mark is the average of the three marks.

 

Final_Mark = (Mark_1*Weight_1 + Mark_2*Weight_2 + Mark_3*Weight_3)/(sum of all weights)

 

When we plug-in the values that are given, we get:

 

90 = (89.8*35 + 95.8*20 + Mark_3 * 45) / (35+20+45)

 

 

Then you solve for Mark_3.