Question

there was a group of 7 people they had a food of month. some more people joined them the food and lasted for only 21 days how many people joined them

Answer 1

Hello Friend...☺

Using Inverse Proportion:

7 people had food for 30 days...

7+X people have food for 21 days...

7×30 = (7+X)×21

21X = 210 - 147

X = 63÷21

X = 3

Three more people joined them...