Answer: [tex]\dfrac{7}{20}^{th}\ \text{Part}[/tex]
Step-by-step explanation:
Given
George weeded [tex]\frac{1}{4}[/tex] of the garden
When they both finish, [tex]\dfrac{2}{5}[/tex] of the garden still needed to be weeded
Suppose Summer weeded [tex]\dfrac{1}{x}[/tex] part
[tex]\Rightarrow \dfrac{1}{4}+\dfrac{1}{x}=1-\dfrac{2}{5}\\\Rightarrow \dfrac{1}{4}+\dfrac{1}{x}=\dfrac{3}{5}\\\Rightarrow \dfrac{1}{x}=\dfrac{3}{5}-\dfrac{1}{4}\\\Rightarrow \dfrac{1}{x}=\dfrac{12-5}{20}=\dfrac{7}{20}[/tex]
So, summer weeded [tex]\dfrac{7}{20}\ ^{th}[/tex] part of the garden
