Question

A man rides at the rate of 18 km/hr. but stops for 6 mins. to change horses at the end of every 7th km. The time that he will take to cover a distance of 90 km is

Options

• 6 hrs

• 6 hrs. 12 min

• 6 hrs. 18 min

• 6 hrs. 24 min

Answer 1

6 hrs. 12 min

Explanation:

90 km = 12 × 7 km + 6 km

To cover 7 km total time taken = `7/18` hours + 6 min = `88/3` min

So (12 × 7 km) would be covered in `(12 xx 88/3)` min and remaining 6 km is `6/18` hrs or 20 min

∴ Total time = `1056/3 + 20`

= `1116/(3 xx 60)` hours

= `6 1/5` hours

= 6 hours 12 minutes.