Question

If two cows and three horses cost ` 4,000 and three cows and two horses cost ` 3,500, how much does a cow cost ?
(a) ` 1,500 (b) ` 1,000
(c) ` 500 (d) ` 2,000

Answer 1

let cost of a cow =xRs
and cost of a horse=yRs
According to Ques.
2x+3y=4000..........(1)
3x+2y=3500........(2)
now solving 1 and 2 ,we get
5x=2500
x=500. ,so your option is (c)

Answer 2

Let the cost of 1 cow = x
and cost of 1 horse = y

According to the question we have,
2x + 3y = 4000. ....(1)

3x + 2y = 3500. .......(2)

from eq.. (1)

2x = 4000 - 3y ......(3)


substituting this in eq.... (2)

3(4000 - 3y) + 2y - 3500


12000 - 9y + 2y - 3500

-9y + 2y = 8500

7y = 8500

y = 8500/7. .......(4)


putting this value in .....(3)


2x = 4000 - 3* 8500/7

2x = 4000 - 25500/7

2x = 2500/7

x = 2500/7/2

x = 2500/14


hence, the cost of 1 cow = Rs 178.58

hope it helps you