There are two boxes with coins inside. The first box has 8 pennies and 2 nickels
ID: 3224633 • Letter: T
Question
There are two boxes with coins inside. The first box has 8 pennies and 2 nickels. The second box has 3 pennies and 6 nickels. If one coin is taken at random from each box, find the probability that; a) they both are pennies. b) the first coin is a penny and the second is a nickel. c). exactly one is a penny. d), their value adds up to at least 5 cents. The probability that Chris will pass a certain biology exam is 6; Katie's probability is .9; Jonah's is .7; Britney's is .75. What is the probability that at least one of them will pass?Explanation / Answer
a. They both are pennies
= (8/10)*(3/9)
= .267
b. The first coin is a penny and 2nd a nickel:
= (8/10)*(6/9)
= .533
c. P( exactly 1 is penny)
= P( either 1 is a penny)
= .5(8/10) + .5(3/9)
= .567
d. P( end up with total 5 cents)
We get alteast 1 penny for this otherwise the sum is not going to be 5cents
= 1- P( no nickels)
= 1- P( both pennies)
= 1- (8/10)(3/9)
= .733