8. there are 10 balls in a bag numbered from 1 to 10. three balls are selected at random without replacement.
a. how many different ways are there of selecting the three balls?
b. what is the probability that one of the balls selected is the number 5?

a. 720

b. 0.3

Step-by-step explanation:

a.

Three balls are selected at random without replacement.

First ball can be selected in 10 ways

Second ball can be selected in 9 ways

Third ball can be selected in 8 ways

Thus, there are 10×9×8 =720 different ways of selecting three balls.

b.

There are three cases that satisfy this condition

Each probabilities are:

Thus, one of the balls selected is the number 5 is then

answer: no

step-by-step explanation:

you are only given the cost not the amount of pounds.

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.