Hikers and other outdoor enthusiasts have a new concern, the Zika virus. Physicians are recommending that people use a mosquito repellant while in areas where mosquitoes are present. A statistician estimated that 80% of hikers would be spraying themselves with mosquito repellant. Suppose that a sample of 10 hikers is asked whether they are using repellant. Find the following probabilities.

a. 9 or more are using repellant

b. Exactly 8 are using repellant

c. 7 or fewer are using repellant