Question

formulate a pair of linear equation in two variables 3 pens and 4 books together cost rs.50 where as 5pens and 3books together cost rs.54​

Answer 1

Given,

Let the cost of pen be Rs. x and books be Rs. y,

According to the question,

3x+4y = 50 ...(i)

5x+3y = 54 ...(ii)

Multiplying (i) by 3 and (ii) by 4, we get,

9x+12y = 150 ...(iii)

20x+12y = 216 ...(iv)

Substracting (iii) by (iv), we get,

-11x = -66

x = 6

Value of y = 9(6) + 12y = 150

= 54+12y = 150

= 12y = 96

= y = 8

The Cost of Pen is Rs.6 each and Book is Rs.8 each.

I hope this helps.