The answer is 8
Happy studying!
And or both means we multiply the given probability situations that are mutually exclusive and exhaustive - they cannot occur at the same time.
let P(a)=x
then: P(b) * P(a) =3/4
15/16 * x = 3/4
15x/16 = 3/4
therefore x= 3/4 *16/15
x = 4/5
P(a) = 4/5
hope it's clear
8 1/4 is given as a positive number so you could write it as +8 1/4
The opposite of positive is negative, so you would have -(+8 1/4)
The answer is A