Question

a box contains a penny, a nickel, a fime, and a quarter. if teo coins are selected without replacement, the probability of getting an amount greater than 11 cents is

Answer 1

P(A) = n(E)/n(S)

Where P(A) is the probability of an event A

n(E) is the number of favorable outcomes

n(S) is the total number of events in the sample space.

Penny means a cent, a nickel means 5 cents, a fine means 10 cents and a quarter means 25 cents.

Total cases = (4*3)/2 = 6

There will be two cases where the sum of 2 coins won't be greater than 11, which are 1+5 and 1+10. The rest 4 cases will be when the sum is greater than 11.

P = Cases when the sum is greater than 11 / Total cases

P = 4 / 6 = 2 / 3 = 0.67

The required probability is 0.67.