Step-by-step explanation:
(1)
The probability of landing on the color gray ONCE
= 2/7
Since it is spun 35 times, the expected number of times that it lands on a gray will be
(2/7 × 35) = 10 times
(2)
The probability of landing on the color black ONCE
= 1/7
Since it is spun 105 times, the expected number of times that it lands on a black will be
(⅐ × 105) = 15 times
The formula is:
Expected value = (Number of spinning)×(probability of landing on a colour)
