Answer:
Thank you very much :) needed that
So,
0.2(n - 6) = 2.8
Distribute.
0.2n - 1.2 = 2.8
Add 1.2 to both sides.
0.2n = 4
Divide both sides by .2.
n = 20
Check.
0.2(20 - 6) = 2.8
Simplify inside parentheses.
0.2(14) = 2.8
Multiply.
2.8 = 2.8 This checks.
S = {2.8}
Multiply the number of tosses by the percent of heads:
20 tosses x 0.75 = 15
The answer is 15.