That would be a $14.13 tip
so 78.52+14.12= 92.65
$92.65
The problem above is an example of conditional probability. From the name itself, it gives you a condition that a certain event has already happen, or is sure to happen. In this case, the probability would be 100% or 1. The condition says that the probability is 100% if the packages are more than 3. Since, 4 is considered to be more than 3, then the probability is 100%.
20*1.95 =39 girls
26girls/39girls =0.667
0.667*100 = 66.67%