The sum of the three numbers is 180. The first number is 10 more than the mean of the three numbers and the second number is 4 less than the mean. What is the third number?

The third number (c) is 54.

The other ones are 70 and 56.

Step-by-step explanation:

We have 3 numbers, let's call them a, b and c.

We know that the sum of the three numbers is 180, thus:

We also know that the first number is 10 more than the mean of the three numbers (Note: the mean is the sum of the numbers divided by the number of numbers). Thus:

Finally the second number is 4 less than the mean:

Now we have our set of equations and we can proceed to solve them:

Solving for a in our first equation we have: and substituting this in our second equation we have:

Now taking this last result into our first equation we have:

Now we are going to solve for b in our second equation and substitute this in our third equation:

But we know that a =70, so we can substitute it in our last line:

Now we just need to find b and we can use our first original equation to do this:

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk