The product of 12 and y increased by 11

Loss% = 9%

Step-by-step explanation:

Here,

CP of both cows=Rs.10,000

Let CP of one cow be Rs.x

CP of another cow be Rs.(10,000-x)

Now,

CP=x ,loss%=30%

SP1 = CP(100 - L%)/100

= x(100 - 30)/100

= 70x/100

=7x/10

Again, CP =Rs.(10,000 - x), Profit%=30%

SP2 = CP(100 - P%)/100

= (10,000 - x)(100+30)/100

= 130 (10,000-x)/100

= (130000 - 13x)/10

According to the question,

SP1 = SP2

7x/10 = 130000 -13x

7x+13x = 130000

20x = 130000

x=6500

Then,

SP1 = (7× 6500)/100 =Rs4550

Total SP=2×4550 = Rs.9100

Since,

CP>SP, loss is made

loss = CP- SP=Rs.(10,000- 9100)=Rs.900

loss%= (loss/ CP)×100%

= (900/10,000)×100

= 9% ans

I hope it helps!!