Maria's average grade for 6 subjects is 85. Her average in mathematics is 90. What is the average of the other 5 subjects?

Question

 My question is a word problem and I need help with using a strategy to solve.

Answer 1

the underlying formula that you want to use here is

(90 + 5x)/6 = 85 because the average across all 6 needs to be 85

solving that algebraically for the value of "x" yields

90 + 5x = 510

5x = 420

x = 84

meaning that her average grade for the other 5 subjects is 84

Answer 2

So, her average over 6 courses is 85. Her math average is 90.

The sum of her six courses divided by 6 = 85.

 

let a,b,c,d,e,90 equal her individual course scores. We know that her math score is 90.

 

(a+b+c+d+e+90)/6 = 85

a+b+c+d+e+90 = 510

a+b+c+d+e = 420

(a+b+c+d+e)/5 = 420/5 = 84

 

So Maria's average in her other 5 courses is 84.

Answer 3

The average is the sum of each grade divided by 6

 

Ave  = ( G1 + G2 + G3 + G4 + G5 + G6 ) /6

 

85 =               "

 

85 * 6 =   ( G1 + G2 + G3 + G4 + G5 + G6 )

 

510 = ( G1 + G2 + G3 + G4 + G5 + G6 )

 

sub 90 for one of the grades

 

510 = G1 + G2 + G3 + G4 + G5 + 90

 

510 - 90 =  420 => gives the sum from the other 5 classes

 

420 = G1 + G2 + G3 + G4 + G5

 

420/5 =  84   which would be  the average of the other 5 classes if Math was removed

 

HTH