Probability of an event happening is 0.77. what's the probability that the event doesn't happen ​

0.23

Step-by-step explanation:

To find this answer you want to subtract the probability of the event happening (0.77) from one in order to find the probability of it not happening.

1-0.77=0.23

a) The odds that such a taxpayer will be audited is 4%.

b) The odds against such a taxpayer being audited is 96%.

Step-by-step explanation:

a) Data and Calculations:

The probability of an IRS audit = 3.8% for U.S. taxpayers who file form 1040 and earned $100,000.

This is the same as the odds that such a taxpayer will be audited.  Odds is the likelihood or chance that an event will take place.

b) The probability of not being audited is 100 - 3.8% = 96.2%

The odd against being audited is the likelihood or chance that an event will not take place.