If there are 12 books in the rack, a person has to choose 5
out of them. In how many ways
can he choose s books
book is
never selected,
how many ways
If one book is never selected​?

462 ways

Step-by-step explanation:

One book never selected means 12 - 1 = 11.

So to find the number of ways, 11C5 which equals to: 11!/(5!(11-5)!) = 462

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.

the answer is the third / last answer

step-by-step explanation: