Answer:
[tex]6\frac{2}{3}\ hours[/tex]
Step-by-step explanation:
step 1
we know that
Frankie can plant a garden by herself in 10 hours
so
100% of the work -------> 10 hours
Using proportion
Find the percentage he can do in 1 hour
[tex]\frac{100\%}{10}=\frac{x\%}{1} \\ \\x=100/10\\ \\x=10\%[/tex]
step 2
we know that
When her son Garyn helps her, the total time it takes them to plant the garden is 4 hours
so
100% of the work (Frankie and Garyn) -------> 4 hours
Remember that
Frankie in 1 hour can do 10%
so
Frankie in 4 hours can do----------> 10%*4=40%
therefore
Garyn in 4 hours can do--------> 100%-40%=60%
step 3
using proportion
Find how long would it take Garyn to plant the garden himself
[tex]\frac{60\%}{4} =\frac{100\%}{x}\\ \\x=4*100/60\\ \\x= 6\frac{2}{3}\ hours[/tex]
