Question

The number of birds on each of the islands X and Y remains constant from year to year; however, the birds migrate between islands. After one year, 20 percent of the birds on X have migrated to Y, and 15 percent of the birds on Y have migrated to X. ?If the total number of birds is 14, 000, how many birds are on island X????

the options given area) 2,800.b) 6,000.c) 6,788.d) 7,212.
e) 8,000.

Answer 1

Answer: Option 'b' is correct.

Explanation:

Since we have given that

Total number of birds = 14000

Let the number of birds on X be 'x'.

Let the number of birds on y be 14000-x

After one year, 20 percent of the birds on X have migrated to Y, and 15 percent of the birds on Y have migrated to X.

but The number of birds on each of the islands X and Y remains constant from year to year.

So, the equation would be

`(20)/(100)x=(15)/(100)(14000-x)\\\\0.2x=0.15(14000-x)\\\\0.2x=2100-0.15x\\\\0.20x+0.15x=2100\\\\0.35x=2100\\\\x=(2100)/(0.35)=6000`

Hence, there are 6000 birds on island X.

Hence, Option 'b' is correct.