CDS Model Paper 3 Mathematics

Heera dealt some cards to Mohan and himself from a full pack of playing cards and laid the rest aside. Heera then said to Mohan, "If you give me a certain number of your cards, I will have 4 times as many card as you have. If I give you the same number of cards, I will have thrice as many card as you have." How many cards did Heera have?