Since they are in ratio we have,
3X + 5x/2 +7x/10 =155 ( since 50 paise is half of a rupee and 10 paise is 1/10 of a rupee.
After taking L C M and cancellations we get,
So we get ,
75one rupee coins and 125 fifty paise coins and 175 ten paise coins.
Hope it helps ....
Have any doubts pls ask