An archer has a probability of 07of hitting a target The arc

An archer has a probability of 0.7of hitting a target. The archer Shoots 10 arrows. Find these probabilities:

a) Hitting the target exactly 7 times

b)Hitting the target at least 7 times

c) hitting the target between 4 and 7 times inclusive

a) probability of hitting the target exactly 7 times = (10C7)*0.7^7*0.3^3
=0.2668

b) probability of hitting the target atleast 7 times=(10C7)*0.7^7*0.3^3 + (10C8)*0.7^8*0.3^2 + (10C9)*0.7^9*0.3 + (10C10)*0.7^10
=0.6496

c)probability = (10C4) *0.7^4*0.3^6 + (10C5)*0.7^5*0.3^5 + (10C6)*0.7^6*0.3^4 + (10C7)*0.7^7*0.3^3
=0.6066