Ans 3..
a) to get an odd score each time we should get odd number so that after adding all 3 odd number give us odd score.
so all 3 spin are independent. ao probability of getting odd number in each spin
= odd numbers / total numbers = 3/4
as there are 3 odd numbers (1, 3, 5)
now probability of getting score odd number is = 3/4 × 3/4 × 3/4 = 27/64
b)
to get probability of score greater than 3 we should get number greater than 1 in 2 chance out of 3.
means if we get 1 in each chance we wull get score 3 but in all other cases we will get score greater than 3 . so we will calculate probability of getting 1 in each spinning and will negate it to get our answer.
so probability to get 1 in each spin = 1/4 × 1/4 × 1/4 = 1 / 64
so probablity to get score more than 3 will be. = 1 - 1/64 = 63/64
and 4
a )
as we know sum of probability of all individual event must be 1
so 3x + x + 4x = 1
8x = 1
x = 1/8
p(1) = 3/8
p(2)= 1/8
p(3)= 4/8
b )
to get score multiplication odd we must get odd number in each spin
so probability = probability of odd × probablity of odd
= (p(1) +p(3) )(p(1) + p(3))
= (3/8 + 4/8)× (3/8+4/8)
= 7/8 × 7/8 = 49/64
