Philip is tossing a coin for 20 times he can get 5 point if the head is up otherwise he loses 3 points as the result he get the total of 4 how many times is the head up?
Assume he gets heads h times; then he must get tails 20-h times. So
5*h - 3*(20-h) = 4
5h - 60 +3h = 4
8h - 60 = 4
8h = 64
h = 8
He threw heads 8 times.
