Answer:
1 hours
Explanation:
By concept we know it takes a person to complete a job of three person more time. so we shall multiply in this question.
if 25 men takes 4 hours
1 men will take 4 * 25 = 100 hours
100 men takes = ( 100 ÷ 100 ) hours = 1 hours
It takes 1 hours for 100 men to build the same wall.