Dear Student,
Let the number of cards with Mohan be x.
So, the number of cards with Ramesh = Total cards - cards with Mohan = 804-x
After Mohan gives 18 cards to Ramesh,
Cards with Mohan= x-18
Cards with Ramesh = 804-x+18 = 822-x
Ramesh's cards = 3× Cards with Mohan
822-x = 3(x-18)
822-x= 3x-54
3x+x= 822+54
4x = 876
x = 876/4 = 219
Number of cards with Mohan in the beginning = x= 219 Ans.
Regards