If a pen costs ₹x and a pencil costs ₹y ,what is the cost of 5 pens and 9 pencils ?
Given ,
Cost of one pen =₹x
So, Cost of 5 pens = ₹5x.
Cost of one pencil = ₹y.
Cost of 9 pencils = ₹9y.
Cost of 5 pens and 9 pencils = ₹5x+9y
Hence , cost of 5 pens and 9 pencils is ₹5x+9y
One pencil costs ₹3 and one fountain pen costs ₹19. What is the cost of x pencils and y fountain pens ? Further , find the cost of 8 pencils and 4 fountain pens.