Answer:
x = 24
Step-by-step explanation:
1.) put the equations together and equal them to 180
2x + 4 + 6x - 16 = 180
2.) combine like terms
8x - 12 = 180
3.) divide both sides by 8
8x = 192
4.) simplify
x = 24
Answer:
10
Step-by-step explanation:
Let c = sum of ages of all children.
mean age of all children = c/15 = 7
c = 15 * 7 = 105
The sum of the ages of all children is 105.
Let b = sum of ages of the 9 boys.
mean age of boys = b/9 = 5
b = 9 * 5 = 45
The sum of the ages of the boys is 45.
The sum of the ages of the girls is c - b.
c - b = 105 - 45 = 60
The number of girls is 15 - 9 = 6
mean age of girls = (sum of ages of the girls)/(number of girls) =
= 60/6 = 10
476.00×5%=23.80 tax=476+23.80=499.80
499.80×15%=74.97
499.80+74.97=574.77
The number of hours required for 3 tractors to plow the field is 2.4 hours
<em><u>Solution:</u></em>
Given that 5 tractors can plow a field in 4 hours
We have to find out number of hours required for 3 tractors to plow the field
5 tractors can plow a field in 4 hours, So time taken for 1 tractor
![\text{ time taken for 1 tractor } = \frac{\text{ time taken for 5 tractor}}{5}](https://tex.z-dn.net/?f=%5Ctext%7B%20time%20taken%20for%201%20tractor%20%7D%20%3D%20%5Cfrac%7B%5Ctext%7B%20time%20taken%20for%205%20tractor%7D%7D%7B5%7D)
![\text{ time taken for 1 tractor } = \frac{4}{5} \text{ hours }](https://tex.z-dn.net/?f=%5Ctext%7B%20time%20taken%20for%201%20tractor%20%7D%20%3D%20%5Cfrac%7B4%7D%7B5%7D%20%5Ctext%7B%20hours%20%7D)
<em><u>So time taken for 3 tractors is given as:</u></em>
time taken for 3 tractor = time taken for 1 tractor x 3
![\text{ time taken for 3 tractor} = \frac{4}{5} \times 3 = \frac{12}{5}](https://tex.z-dn.net/?f=%5Ctext%7B%20time%20taken%20for%203%20tractor%7D%20%3D%20%5Cfrac%7B4%7D%7B5%7D%20%5Ctimes%203%20%3D%20%5Cfrac%7B12%7D%7B5%7D)
![\rightarrow \frac{12}{5} = 2.4](https://tex.z-dn.net/?f=%5Crightarrow%20%5Cfrac%7B12%7D%7B5%7D%20%3D%202.4)
So number of hours required for 3 tractors to plow the field is 2.4 hours