There are 10 books on a shelf, of which 4 are paperbacks and 6 are hardbacks. how many possible selections of 5 books from the shelf contain at least one paperback and at least one hardback? a75 b120 c210 d246 e252

The answer is d (246)

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value