The cost prices of two articles A and B are in the ratio 4 : 5. While selling these articles, the shopkeeper gains 10% on article A and 20% on article B and the difference in their selling prices is ₹480. The difference in the cost price (in ₹) of articles B and A is :

300

             A                 B

CP        4         :        5

SP       4.4       :        6

Difference between SP = 6 - 4.4 = 1.6

1.6 = 480

CP difference = 1 = 300