A) 7 days
B) 8 days
C) \[7\frac{1}{2}\,\,\text{days}\]
D) \[6\frac{1}{2}\,\,\text{days}\]
Correct Answer: C
Solution :
Let the son take x days to do the work. \[\therefore \] \[\frac{1}{5}+\frac{1}{x}=\frac{1}{3}\] \[\Rightarrow \] \[\frac{x+5}{5x}=\frac{1}{3}\] \[\Rightarrow \] \[3x+15=5x\] \[\Rightarrow \] \[2x=15\] \[\Rightarrow \] \[x=\frac{15}{2}\] \[=7\frac{1}{2}\,\,\text{days}\]You need to login to perform this action.
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