20 men, 10 women and 10 children are in a competition. The mean score for the women is 15.6.
The mean score for the children is 9.2.
Kevin says that the mean score for all 40 people is 11.2.
Work out the mean score for men

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15

hd extra 3-7 x d en is the answer