Question

It's holds same size discs there are five red six White and seven blue you pick a disk record the colour then put it back in if you do this 250 more times how many times can you expect to pick either a red or white disk?

Answer 1

Total number of disks . . . . . 18

Number of red disks  =  5
Number of white disks  =  6

Number of (red or white) disks  =  (5 + 6)  =  11

Probability of selecting a (red or white) disk  =  11/18 .

Number of expected successes in 251 draws = (11/18) x (251)  =  153 .