The speeds of a bicycle and a scooter are in the ratio 7:16 . If the person…
2024
The speeds of a bicycle and a scooter are in the ratio 7:16 . If the person riding the bicycle increases the speed by 5 km/hr , then the new ratio becomes 1:2 . What is the initial speed of the bicycle ?
- A.
80 km/hr
- B.
70 km/hr
- C.
40 km/hr
- D.
35 km/hr
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Correct answer: D
Answer: 35 km/hr
Let the bicycle's speed be 7x km/hr and the scooter's speed be 16x km/hr.
After increasing the bicycle speed by 5 km/hr, the new speeds are 7x + 5 and 16x, and the new ratio is 1 : 2. So (7x + 5)/(16x) = 1/2.
Solve the equation: 2(7x + 5) = 16x → 14x + 10 = 16x → 10 = 2x → x = 5.
Initial bicycle speed = 7x = 7·5 = 35 km/hr. Check: (35 + 5) : (16·5) = 40 : 80 = 1 : 2, which matches the given condition.