There are 32 pupils in Mr Patel's class. There are 18 girls and 14 boys. All the pupils took a Maths test. The mean score for the girls was 79%. The mean score for the boys was 83%. Work out the mean score for the whole class.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

%40

step-by-step explanation:

14

step-by-step explanation:

14

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.