Question

25. 37 pens and 53 pencils together cost Rs 320, while 53 pens and 37 pencils together cost Rs 400. Find the cost of a pen and that of a pencil.

Answer 1

let take the value of pen = x
the cost of pencil =y.
the cost of 37 pens =37x
the cost of pencil =53y

total cost = 37x + 53y. =320. -equation (1)

now make second equation

the cost of 53 pens = 53x
the cost of 37 pencils = 37y

total cost = 53x + 37y = 400 -equation (2)

compare equation (1) and (2)

37x + 53y = 320
37x = 320-53y
x = (320 -53y) / 37

equation no. 2

53x + 37 y =400
putting the value of x in equation
53(320-53y )/37 + 37 y = 400

now you can solve or find the value of y the x we take