A and B are 90 km apart they start to move each other simultaneously A at speed 10 and B at 5 km/hr if every hour they double their speed what is distance that A pass until he meet B?
Pick one
A) 30 km B) 40 km C) 50 km D) 60 km E) 70 km

Rationale: in 2 hours a covers ( 10 + 20 ) = 30 km b covers ( 5 + 10 ) = 15 km , total covered = 45 in the next hour they have to cover ( 90 - 45 ) km with the speeds 40 km / hr and 20 km / hr respectively let them take another t hrs to meet so sum of the distance to be covered by both is 45 km ( 40 * t ) + ( 20 * t ) = 45 km gives t = ( 3 / 4 ) hrs we need to fid out the distance covered by a which equals to = 30 + ( 40 * ( 3 / 4 ) ) = 60 km answer : d
Answer: D