Sharon and Karen

[BMAD]

Two algebra students decide to save time on their homework by sharing the work equally. But after a while Karen has only done three-fifths of the problems that Sharon has left, which in turn is four-sevenths of the amount that Sharon has done. How much faster must Karen work than Sharon,if they care to finish simultaneously?

[Barcallica]

either 1.45 or 2.15 defending on interpretation of what which meant

[Nins_Leprechaun]

Karen must now work 1.45 times faster than Sharon in order for them to complete there work simultaneously

[BMAD]

There are two interpretations of what the "which" (in turn) referred to...

so there is a separate answer out there that is equally plausible.

[DeathStone0000]

I think Karen should work 1.443 times faster than Sharon does.