Q. If x can finish a job in 4 hours and y can finish the same job in 8 hours independently, then they together will finish the job in :
Answer: 160 minutes
Notes: (x + y)'s 1 day's work $latex = \frac{1}{4}+\frac{1}{8} = \frac{2+1}{8} = \frac{3}{8}&s=1$ ∴ Required Time $latex = \frac{8}{3}\ hours&s=1$ $latex = \left ( \frac{8}{3}\times 60 \right )\ minutes&s=1$ $latex = 160\ minutes$ Hence option [D] is correct answer.

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