Answers

2016-02-15T17:30:44+05:30
21/2 = 10.5

90    -      10.5
30    -       ?

30 x 10.5 
    90

10.5 / 3
3.5
3.5 hours are required for car to travel 30 km
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2016-02-15T17:42:43+05:30
-->21/2hr = 10.5hr
-->90km  in  10.5hr
-->30km  in   ??
--> 30 x 10.5 /90
--> 10.5 / 3 = 3.5
3.5 hours are required for the car to travel 30 km.
2 4 2