(6) The total cost of 6 books and 7 pens is 79 rupees and the total co – InterviewSolution

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1.	(6) The total cost of 6 books and 7 pens is 79 rupees and the total cost of 7 books and 5 pensis 77 rupeess. Find the cost of 1 book and 2 pens.
Answer» Let the cost of the book be xAnd the cost of pen be yThen the cost of 6 books n 7 pens is6x+7y = 79And 7x+6y = 77Now let us add both equations13x + 13y = 156X+y = 12Let us subtract both equations-x + y = 2Now let us add the equations so obtained thenX-x + y +y = 12 + 22y = 14y = 7Substitute in one equation thenX + 7 = 12X = 5So the cost of one book is 5And one pen is 7So the cost of 1 book and 2 pens isX + 2y = 5 + 2(7) = 5 + 14 = 19

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