C) 13
The y value adds one by every x; therefore 4 would be 13.
I can answer 18 for you, but I don't understand 16
18. Since when we lose 3 girls the ratio for the girls side drops by 1, that tells us that 1 digit equals 3 people.
a) 5*3=15 so our answer is 15 girls.
b) 4*3=12 and 5*3=15 so 15+12, our answer would be 27
You are given the height of the building and the length of the shadow the building gives, so you can set that up as a proportion of Height of building over the length of the shadow so 31/28.
Now you can set the same proportion for Julian, using X for her height, so you would have x/6.
To solve for her height, set the two proportions equal and solve for x:
31/28 = x/6
Cross multiply:
31 * 6 = 28 *x
186 = 28x
Divide both sides by 28:
x = 186 / 28
x = 6.64 feet tall