Answer:
1.5 hours
Step-by-step explanation:
we know that
1) Martha can paint a room in 2 hours
so
Martha can paint the 100% of the room in 2 hours
Find out what percentage of the room she can paint in an hour
using proportion
![\frac{100\%}{2}=\frac{x}{1}\\\\x=100\%/2\\\\x=50\%](https://tex.z-dn.net/?f=%5Cfrac%7B100%5C%25%7D%7B2%7D%3D%5Cfrac%7Bx%7D%7B1%7D%5C%5C%5C%5Cx%3D100%5C%25%2F2%5C%5C%5C%5Cx%3D50%5C%25)
2) Jamie can paint a room in 6 hours
so
Jaimie can paint the 100% of the room in 6 hours
Find out what percentage of the room she can paint in an hour
using proportion
![\frac{100\%}{6}=\frac{x}{1}\\\\x=100\%/6\\\\x=16.67\%](https://tex.z-dn.net/?f=%5Cfrac%7B100%5C%25%7D%7B6%7D%3D%5Cfrac%7Bx%7D%7B1%7D%5C%5C%5C%5Cx%3D100%5C%25%2F6%5C%5C%5C%5Cx%3D16.67%5C%25)
3) In one hour Martha and Jamie can paint
![50\%+16.67\%=66.67\%](https://tex.z-dn.net/?f=50%5C%25%2B16.67%5C%25%3D66.67%5C%25)
so
using proportion
Find out how long will it take them to paint the 100% room together
![\frac{1}{66.67\%}=\frac{x}{100\%}\\\\x=100/66.67\\\\x=1.5\ hours](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B66.67%5C%25%7D%3D%5Cfrac%7Bx%7D%7B100%5C%25%7D%5C%5C%5C%5Cx%3D100%2F66.67%5C%5C%5C%5Cx%3D1.5%5C%20hours)
A = 1/4 * (pi) * d^2
A = 1/4 * (pi) * 8^2
A = 1/4 * (pi) * 64
A = 1/4(64) * (pi)
A = 64/4 * (pi)
A = 16 (pi) in^2
Answer:
36
Step-by-step explanation:
The answer is 102 because you subtract 180-78.