X and Y in the following weave are warp and weft, respectively.
Qus1. Rekha and Meeta can weave a sweater in 12 days ,Meeta and Payal in 15 days, Payal and Rekha in 20 days. In how many days will they weave it, if they weave together ? In how many days will each of them weave, if they weave it alone?