Question

Ami started walking on a tread mill at 8:00 AM at a constant speed of 6 km/hr. 15 minutes later Avni arrived and started walking on another tread mill at a constant speed of 8 km/hr. Sometime later Kareena arrived and started walking on another tread mill at a constant speed of 9 km/hr. When all the three stopped at the same time they found that they had walked the same distance. For how much time (in minutes)did Kareena walk on tread mill?​

Answer 1

Answer:

Did the Karena covered 11 km/hr

Answer 2

Answer:

Kareena walks on the tread mill for 40 Minutes.

Step-by-step explanation:

Ami

Ami started walking on the treadmill at 8:00 AM.

Speed= 6km/hr

Distance covered by Ami in 1 hour, till 9:00 AM = 6Km.

Avni

Avni started walking on the treadmill at 8:15 AM.

Speed= 8km/hr

Distance covered by Avni till 9:00 AM,

Distance covered in 60 minutes = 8 km

                              in 45 minutes= $\frac{8}{60}$ × $45$.

                                                     = 6 km.

So we can say that till 9:00 AM, Ami and Avni covered the same distance.

Kareena

Speed= 9km/hr

Time taken by Kareena to cover 6 km,

In 60 minutes she covers 9 km,

For 1 km time taken = $\frac{60}{9}$ minutes.

     6 km time taken = $\frac{60}{9}$ × 6 minutes.

                                 =  40 minutes.

For covering 6 km in 40 minutes till 9:00 AM, she will start at 8:20 AM.

So Kareena will start walking on the treadmill at 8:20 AM to cover 6 km till 9:00 AM. So that when they stop at the same time (9:00 am) they walked the same distance (6 km ).