Answer:
We have been given that
72 persons has enough food for 7days.
After 1 day they decided to finish the food in remaining 3 days.
We need to find number of invitees to finish the food.
After one day there are 72 people and they have food for 6 days.
If people are changed n times, time will change to (1/n) of initial time.
\frac{1}{n}\times 6\ =\ 3n1×6 = 3
Therefore n = 2
Total number of people needed = n × 72
Total number of people needed = 72×2
Total number of people needed = 144
Hence the number of invitees = 144 - 72 =72
72 people are invited to finish the food in 3 days
