84 x .70 = $58.80
Or if you want to do it the long way you can calculate the actual discount (your savings from this purchase first then subtract it from the original price of $84. It`s just easier to figure out what is left (which is 70% of $84).
What information is givin to you to get that awnser?
Formula for Volume of Cylinder you need the radius
This is the formula for percentage increase and decrease
