Answer:
If 20 more soldiers join it would last 48 days
Step-by-step explanation:
if 80 soldiers need 84000 food for 60 days it means that in 60 days one soldier eats 84000/80= 1050 each
then 1050/60=17.5 meaning they need 17.5 food a day each,
adding 20 soldiers means 80+20= 100 soldiers
100*17.5=1750 food is eaten every day
84000/1750= 48 which means that 100 soldiers will eat 84000 in 48 days