Question

three books and a pen cost is Rs 70 and 2 pen and a book cost Rs 40 how much wil a book and a pen cost is ?​

Answer 1

Answer:

3 book and one pen is cost rs 70

a=3 b=1

a+b/70

3+1/70

4/70

70/4

=17.5

a=1 b=2

a+b/40

1+2/40

3/40

13.33

Answer 2

Answer:

let the cost of the book is = x

and the cost of the pen = y

ATQ

3x + y = 70. and. ------------ eq 1

x + 2y = 40. --------------------- eq 2

now,

3x + y = 70

3x = 70 - y

x = 70 - y /3.

now putting the value of x in eq 2