Question

Sita and Geeta start at the same time to ride from place A to place B, which is 90 km away from place A. Sita travels 3 km per hour slower than Geeta. Geeta reaches place B and at once turns back, meeting Sita 15 km from place B. Geeta's speed (in km/h) is:
1. 7.5
2. 9
3. 10.5
4. 6

Answer 1

Correct Answer - Option 3 : 10.5

Given:

Distance between place A and B = 90 km 

Speed of Sita = Speed of Geeta - 3 km/h 

Formula used:

Ratio of distance = Ratio of speed  (When the time is equal)

Calculation:

Distance travelled by Sita = 75 km 

Distance travelled by Geeta = 90 + 15 = 105 km 

Ratio of Distance in a certain time travelled by Sita and Geeta is equal to the ratio of the speed = 75 : 105 

⇒ 5 : 7 

⇒ 7 - 5 = 2 units = 3 km/h 

⇒ 1 unit = 1.5 km/h 

⇒ 7 = 7 × 1.5 = 10.5 km/h 

∴ The speed of Geeta is 10.5 km/h.