42. If 20 men can eat 200 kg of wheat in 40 days, then 10 men can eat 300 kg of wheat in how many days? a) 120 days b) 60 days c) 80 days d) none of these

Calculate the amount 1 man can eat per day from the known amounts:

200 kg / 40 days = 5 kg of wheat per day / 20 men = 0.25 kg per man per day.

Now calculate the time it will take 10 men:

10 men x 0.25 kg per day = 2.5 kg per day.

300 kg / 2.5 kg per day = 120 days