Three shopkeepers X,Y and Z go to a store to buy stationery items. X purchases 12 dozen marker pens, 5 dozen ink pen and 6 dozen pencils. Y purchases 10 dozen marker pens, 6 dozen ink pen and 7 dozen pencils. Z purchases 11 dozen marker pens, 13 dozen ink pens and 8 dozen pencils. A marker pen cost Rs 40/- , a pen costs Rs. 7/- and a pencil Rs. 1 /- each. Using matrix multiplication calculate the individual bills of X, Y and Z.
