What is the probability of three quarters landing on tails if you know the first one has
landed on tails

1/3 or One-Third

Step-by-step explanation:

If there are 3 coins, the denominator would be 3. You already know that 1 of the coins had landed on tails. 1/3 is the answer.

the image is given below

since the options are not given so we draw it from the equation

the given equation is

y = (x-1) (x+4)

y = y² + 3x - 4

the above equation is a quadratic equation which will have two roots. if we draw the graph for it, it will look like this