we know that
The formula of the surface area of the cone is equal to

where
SA is the surface area
r is the radius of the cone
l is the slant height
in this problem we have

Solve the formula for l

substitute the values

therefore
<u>the answer is</u>
The slant height is 
$1.00 because the first ounce is 0.40 then you have to times the other 3 ounce by 0.20 then u would have $1.00
10/7
Because root of 100 is 10, root of 49 is 7
The answer would be c because I know