Answer: First Option is correct.
Step-by-step explanation:
Since we have given that
Number of hours Chance can wash the car = 2 hours
Number of hours Sandy can wash the car = 4 hours
Work done by Chance per hour is given by
[tex]\frac{1}{2}[/tex]
Work done by Sandy per hour is given by
[tex]\frac{1}{4}[/tex]
Work done by altogether per hour is given by
[tex]\frac{1}{2}+\frac{1}{4}\\\\=\frac{2+1}{4}\\\\=\frac{3}{4}[/tex]
So, Number of hours they take if they together wash the car is given by
[tex]\frac{4}{3}[/tex]
Hence, First Option is correct.