Question

The total cost of 8 book and five Pence is 420 rupees and the total cost of 5 books and eight pens is 321 find the cost of one book and to pen. ​

Answer 1

i) 420÷8= 52.5

ii) 321÷5= 64.2

Answer 2

Answer:

BOOK = 45 AND PEN = 12

Step-by-step explanation:

let no. of pens be y and no. of books be x

∴8x + 5y = 420     ------------------- 1

 5x + 8y = 321      ------------------- 2

Adding And Subtracting the equation

13x + 13y = 741 --------------3

3x   -  3y  = 57 --------------4

3 ⇒ x + y = 57 --------------5

4 ⇒ x - y = 33 ---------------6

Adding 5 And 6

2x = 90

x = 45

Substituting Value In 5

x + y = 57

y = 57 - 45

y = 12

∴ Cost of one book = 45

   Cost of one pen = 12