(6) The total cost of 8 books and 5 pens is 420 rupees and the total c

1.	(6) The total cost of 8 books and 5 pens is 420 rupees and the total cost of 5 books and 8pens is 321 rupees. Find the cost of 1 book and 2 pens.
Answer» Let cost of one book be x and cost of one pen be y 1st.equation 8X + 5Y = 4202nd.equation 5X + 8Y = 321 1st.eq × 5 40X + 25 Y = 21002nd.eq×8 40X + 64Y = 2568 Subtracting(-) 39Y = 468 Y= 12Putting the value of Y in eq.1 we get , X=45 cost of 1book = 45 cost of 2 pen = 2×12=24

(6) The total cost of 8 books and 5 pens is 420 rupees and the total cost of 5 books and 8pens is 321 rupees. Find the cost of 1 book and 2 pens.

Answer»

Let cost of one book be x and cost of one pen be y

1st.equation 8X + 5Y = 4202nd.equation 5X + 8Y = 321

1st.eq × 5 40X + 25 Y = 21002nd.eq×8 40X + 64Y = 2568 Subtracting(-) 39Y = 468 Y= 12Putting the value of Y in eq.1 we get ,

X=45

cost of 1book = 45 cost of 2 pen = 2×12=24