Question

the total cost of 5 pens and 2 book is rupees 150 while total cost of 7 pens and 3 book is rupees 219 find the total cost of 3 pens and one book​

Answer 1

Step-by-step explanation:

pens= x

books=y

5x+2y=150....(1)

7x+3y=219....(2)

multiplying eq 1 by 3 and eq 2 by 2

15x+6y=450....(3)

14x+6y=438....(4)

subtracting equations 3&4 we get

x=12

put this value in eq 1 we get

60+2y=150

2y=90

y= 45

hence

cost of 3 pens= 3*12= 36

cost of one book= 45