A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?
Rs. 375
Rs. 400
Rs. 600
Rs. 800
Explanation:
Cs 1 days work =$ \dfrac{1}{3} $-$ \left(\dfrac{1}{6} +\dfrac{1}{8} \right) $=$ \dfrac{1}{3} $-$ \dfrac{7}{24} $=$ \dfrac{1}{24} $.
As wages : Bs wages : Cs wages =$ \dfrac{1}{6} $:$ \dfrac{1}{8} $:$ \dfrac{1}{24} $= 4 : 3 : 1.
$\therefore$Cs share [for 3 days] = Rs.$ \left(3 \times\dfrac{1}{24} \times 3200\right) $= Rs. 400.