Question

1. If the cost of 37 pens and 53 pencils
together is 320, while 53 pens and
37 pencils together cost 400. The cost of
two pens is
e 26.50
(b) 1.50
c? 13 00
(d) * 15.00​

Answer 1

Answer:

c? 13 00

Step-by-step explanation:

let cost of one pen be x

and cost of one pencil be y

case 1:

37x + 53y = 320            --- Equation (1)

case 2:

53x + 37y = 400            --- Equation (2)

from equation 1 we derive

y = (320 - 37x)/53

inserting this into equation 2

53x + 37((320 - 37x)/53) = 400

=> 53x + $\frac{11840 -1369x}{53}$ = 400

=> 53x -1369x/53 = 400 - 11840/53

=> $\frac{2809x - 1369x}{53}$ = $\frac{21200 - 11840}{53}$

=> 1440x/53 = 9360/53

=> x = 9360/1440

therefore x = 6.5

Cost of one pen = x = 6.5

therefore, cost of 2 pens = 13

Answer 2

Answer:

1.50 is the right answer