A train leaves Amritsar at 6 am & reaches Delhi at 12 noon. Another train leaves Delhi at 8 am & reaches Amritsar at 5 pm. At what time do the two trains cross each other?
A sells an article to B making a profit of 1/5 of his outlay. B sells it to C, gaining 20%. If C sells it for Rs 600 and incurs a loss of 1/6 of his outlay, the cost price of A is