Question

A garrison had food enough for 120 soldiers for 40 days.How many more days would the food last if after 10 days 20 soldiers had to leave?

Answer 1

Answer:

120s * 60d = 7,200 daily rations

120s + 40s = 160 soldiers

7,200r / 160s = 45 days

Answer 2

Answer:

Supposing the men have not left the camp for the remaining days:

The provisions would last 120 men for  (40−10)  days which is 30 days

Now since 20 men have left the camp total men remaining would be  (  120−20) which is 100  

Taking the days which would suffice 100 men as  x  we can apply inverse proportion which is

Taking x as men and y as days

X1/x2=y2/y1  

120/100=x/30  

(6/5)×30=x  

x=36days  

Thus the food would last another 36 days