No it is not necessary that Kelvin will get one head and one tail every time
<u>Explanation:</u>
Probability in math is equal to favorable outcomes/total outcomes
The coin has two sides a head and a tail. When we flip a coin we have 50-50 possibility of getting a head and a tail. It means with every toss we have 1/2 possibility of getting head as well as tail.
But this does not mean that when we toss a coin twice we will get one head at one toss and one tail at another toss.
There is a possibility of getting both heads as well as both the tails.
Let x be the number of cars. We will find out how many cars you have to wash to make as much money as your friend: 10x - 25= 13x - 55 Add 25 on both sides and subtract 13x, also both sides: 3x = -30 Now divide both sides by -3: x= 10 cars you have to wash.