Answer:
Step-by-step explanation:
Add all the scores you do know
8 + 10 + 38 + 20 = 76
Now put in an ex for the situps.
76 + x
There are 5 subjects
(76 + x) /5 = 18.2
The average was 18.2
Multiply both sides by 5
5*(76 + x ) / 5 = 18.2 * 5
Cancel the left combine the right.
76 + x = 91
Subtract 76 from both sides
76 - 76 + x = 91 - 76
x = 15
15
Call the unknown time x.
The mean is the sum of the numbers divided by the number of numbers.
There are 5 numbers.
(8 + 10 + 38 + x + 20)/5 = 18.2
(x + 76)/5 = 18.2
x + 76 = 91
x=1
Substitute the value of y to the first given
3x+4(-x)=-1
3x+(-4x)=-1
-x=-1
divide both sides by -1
2240 scooter
725+579+696=2000
2000*1.12=2240
