The total distance covered is equal to the product of speed and time. The distances that should have been traveled by the two friends in this item should be equal. Let x be the total time that the first among them have walked. The time of the second person should be x - 5/60.
The equation that would best represent their motion is,
3(x) = 4(x - 5/60)
The value of x from the equation is equal to 0.33 hours which is equal to 20 minutes.
Answer: 20 minutes