Use a calculator and divide
The penny can land two ways.
The nickel can land two ways.
The dime can land two ways.
The quarter can land two ways.
The total number of ways that all of them can land is (2x2x2x2)= 16 possibilities.
Only ONE result shows no heads . . .
TAIL-TAIL- TAIL-TAIL.
All of the other 15 possibilities include at least one HEAD. So the probability is 15/16 = 93.25% .
The answer to this question is 7x+1
