# The average

The average of one set of 4 numbers is 35. The average of another set of number is 20. The average of the numbers in the two sets is 30. How many numbers are there in the other set?

Result

n =  2

#### Solution:

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

Be the first to comment!

#### To solve this verbal math problem are needed these knowledge from mathematics:

Looking for help with calculating arithmetic mean? Looking for a statistical calculator? Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?

## Next similar examples:

1. 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?
2. Average
The arithmetic mean of the two numbers is 71.7. One number is 5. Calculate the second number.
3. 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?
Added together and write as decimal number: XXXIV + MDCCXII
5. Toys
The toy shop sold the same number of balls for 62 CZK and skipping ropes for 34 CZK. They income was 576 CZK. How many sold balls and how many skipping ropes?
6. Unknown number 11
That number increased by three equals three times itself?
7. 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?
8. 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?
9. Classroom
In a class are 32 pupils. Boys are 8 less than girls. How many boys and girls are in the classroom?
10. Simple equation
Solve the following simple equation: 2. (4x + 3) = 2-5. (1-x)
11. Find x
Solve: if 2(x-1)=14, then x= (solve an equation with one unknown)
12. Eq1
Solve equation: 4(a-3)=3(2a-5)
13. Simple equation
Solve for x: 3(x + 2) = x - 18
14. Equation 29
Solve next equation: 2 ( 2x + 3 ) = 8 ( 1 - x) -5 ( x -2 )
15. If-then equation
If 5x - 17 = -x + 7, then x =
16. Negative in equation
2x + 3 + 7x = – 24, what is the value of x?
17. Rabbit family
Rabbit family ate 32 pieces of carrots, small one ate 6 pieces, dad 5 more than the mother. How much ate mom?