# Arithmetic average

The arithmetic mean of the five numbers is exactly 8. The sum of these four numbers is 30. What is the fifth number?

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- Average

The arithmetic mean of the two numbers is 71.7. One number is 5. Calculate the second number. - One-third

A one-third of unknown number is equal to five times as great as the difference of the same unknown number and number 28. Determine the unknown number. - Dropped sheets

Three consecutive sheets dropped from the book. The sum of the numbers on the pages of the dropped sheets is 273. What number has the last page of the dropped sheets? - Unknown number 11

That number increased by three equals three times itself? - Unknown number

Identify unknown number which 1/5 is 40 greater than one tenth of that number. - Equation

Solve the equation: 1/2-2/8 = 1/10; Write the result as a decimal number. - Negative in equation

2x + 3 + 7x = – 24, what is the value of x? - Norm

Three workers planted 3555 seedlings of tomatoes in one dey. First worked at the standard norm, the second planted 120 seedlings more and the third 135 seedlings more than the first worker. How many seedlings were standard norm? - Equation

? - Simple equation

Solve for x: 3(x + 2) = x - 18 - Cakes

Grandmother baked cakes. Half of its was poppy, quarter with plum jam and 16 cheesecakes. How many cakes she baked in total? - Forest nursery

In the forest nursery after winter, they found that 1/10 stems died out of them. For them, they land 193 new spruces. How many spruces are in the forest nursery? - Equation 29

Solve next equation: 2 ( 2x + 3 ) = 8 ( 1 - x) -5 ( x -2 ) - 7 roses

Peter buys 7 roses. When he pay for it left him 4 euro. If he bought 5 roses left him 40 euros. How many euros had Peter before buying? - Aunt

Annie aunt is 35 years old, Annie is 14 years. For how many years will aunt have twice as many years as Annie? - Class 8.A

Three quarters of class 8.A went skiing. Of those who remained at home one third was ill and the remaining six were on math olympic. How many students have class 8.A? - Family

Mom is 39 years old. Karl is eight years and Paul 4 years. For many years mother would old just like two children together?