Question

51. If the cost of 37 pens and 53 pencils to-
gether is 320, while 53 pens and 37 pen-
cils togehter cost 400. The cost of two
pens is :​

Answer 1

Answer:

cost of two pens are 6.5+6.5=13rs

Answer 2

Heya,

Let the cost of a pen be Rs x and that of a pencil be Rs y.

The equation simplies to

37x + 53y = 320.......................(1)

53x + 37y = 400.......................(2)

Adding equation (1) and (2),we get :-

90x + 90y = 720.

Simplying I.e. dividing each side by 90.

x + y = 8..................(3)

Again, subtracting equation (2) from (1), we get :-

16x - 16y = 80

Dividing each side by 16,

x - y = 5.............(4)

Now, from equation (3) and (4l, we get

x = 13/2.

Hence, cost of two pens = Cost of one pen × 2.

= 13/2 × 2. = Rs 13.

Regards

Kshitij