Speed is inversely proportional to time. Koma travelled 3 ¹/² hours at 120 km per hour. On the return trip, Koma drove at 100 km/hr, How long will it take him to travel?

To find the time it will take for Koma to travel on the return trip, we can use the formula for inverse proportionality:

Speed1 x Time1 = Speed2 x Time2

For the first trip:
Speed1 = 120 km/hr
Time1 = 3 ¹/² hours = 7/2 hours

For the return trip:
Speed2 = 100 km/hr
Time2 = unknown

Plugging in the values:
120 x 7/2 = 100 x Time2
840 = 100 x Time2
Time2 = 840 / 100
Time2 = 8.4 hours

Therefore, it will take Koma 8.4 hours to travel on the return trip.

Let x be the time Koma will take to travel on the return trip.

Speed is inversely proportional to time. This means that:

Speed ∝ 1/Time

or

Speed = k/Time

where k is a constant of proportionality.

For the first trip, we have:

Speed = 120 km/hr
Time = 3 ¹/² hours

Substituting these values into the equation above, we get:

120 = k/3 ¹/²

Solving for k, we get:

k = 120 × 3 ¹/² = 240

For the return trip, we have:

Speed = 100 km/hr
Time = x hours

Substituting these values into the equation above, we get:

100 = 240/x

Solving for x, we get:

x = 240/100 = 2.4 hours

Therefore, it will take Koma 2.4 hours to travel on the return trip.