a set question (math)?

Question

Set x = (1, 9, 7, 2, 5). What is the difference between the number obtained by arranging the terms in descending orer and the number obtained by arranging the terms in ascending order?
Okay, this is probably pretty easy but I have no idea how to do it. Please explain.
Another question..
A hubcap with an area of 16pi has a radius one-half tat of the wheel it is on. If the wheel were to roll down a 400-foot hill, approximately how many revolutions would it make?

Answer 1

First of all, if you want to say it is a set, you have to write it as such:

x={1, 9, 7, 2, 5}

It is called a "set notation." It does not matter what order you put the numbers within the brackets.

Second question, determine the radius of the hubcap, add the tire height. Then calculate the circumference. Then divide it by 400. Be careful not to confuse the radius with the diameter in the process.

Answer 2

Okay, this is the original set:

set x = (1, 9, 7, 2, 5)

When the terms are arranged in descending order, it looks like this:

set x = (9, 7, 5, 2, 1)

where the difference is: 9 - 1 = 8

When the terms are arranged in ascending order, it looks like this:

set x = (1, 2, 5, 7, 9)

where the difference is: 1 - 9 = -8

The difference is 0; which shows that there really is no difference HOW you arrange the numbers, since the numbers are within parenthesis.

As far as the hubcap question, one half of the 16 is 8, so if it is 8... I really do not know... sorry. I can't figure out how to figure that one out. Maybe you could convert the 400 feet to inches and figure it out that way? 1 foot = 12 inches, so 400 feet is equal to 4800 inches...

Good luck!

Answer 3

97521 - 12579