Saved Bookmarks
| 1. |
Ratio of speed of bike, van and lorry is 3 ∶ 7 ∶ 5. If lorry cover 360 km in 12 hours. Find the average speeds of bike and van together.1. 30 km/h2. 25 km/h3. 20 km/h4. 28 km/h |
|
Answer» Correct Answer - Option 1 : 30 km/h Given: The ratio of the speed of the bike, van and lorry = 3 ∶ 7 ∶ 5 Distance covers by lorry = 360 km Time taken by lorry to cover = 12 hours Concept used: Speed = Distance/Time Average = (Total sum)/(Total terms) Calculations: Let the speed of the bike, van and lorry be 3x, 7x and 5x respectively Speed of lorry = 360/12 = 30 km/h ⇒ 5x = 30 ⇒ x = 6 Speed of bike = 3x = 3 × 6 = 18 Speed of van = 7x = 7 × 6 = 42 Average speed of bike and van = (18 + 42)/2 = 30 km/h ∴ Average speed of bike and van is 30 km/h |
|