You have a collection of 30 coins, all of which are dimes and quarters. The total of your collection is $5.10 how many of each kind of coin do you have

Part 1

A used-car lot has 120 vehicles for sale. Since a sample of 15 of these vehicles finds that 6 of them have previously been in an accident. That means that the probability of finding a an accident car is

when the number of cars is 120, the number of accident cars will be:

Thus the best estimate of the percent of the used-car lot's vehicles that have previously been in an accident is 48.

Part 2

The total sample space of the sums has outcomes.

Out of this, the required events are:

Which is 24 in number.

Thus the probability required is