Question

A train travels 90 km in 1 and a half hours how long will it travel in 3 hour 30 min at the same speed

Answer 1

210........it might be

Answer 2

in 1.5 hours train travels 90 km
in 1 hour train travels 900/15km
in 3.5 hors train travels (900*3.5)/15km
=210km