In a camp, there is enough flour for 300 persons for 42 days. How long will the flour last if 20 more persons join the camp?

∵For 300 persons flour is enough for 42 days.

∴ For 1 person’s flour enough = 300 × 42 = 1260days.

Now, 20more persons join the camp.

SO, total persons = 300 + 20 = 320

∴ for 320 persons flour enough = days