Explanation:
time ∝ number of door 1
time . ∝ 1/number of people. 2
compare equation 1 and 2
time . ∝ number of door / number of people
put k as constant
time = k number of door / number of people. 3
time =2. people=4 door = 10
putting in equation 3
2 = k (10)/(4)
2×4/10 = k
8/10 =k
4/5 =k
putting in equation 3
time= 4/5 number of door / number of people
now time =5 door= 25 people=?
5=4/5 (5)/ (number of people)
number of people =4/5 ×25/5
number of people= 4