Problem Solving

A wildlife preserve is being planned for
3,000 rhinoceroses. The preserve is to
contain a total of 10,000 acres of
watering area, plus 100 acres of
grazing area for each rhinoceros. If the
number of rhinoceroses is expected to
increase by 10 percent, how many
thousand acres should the preserve
have in order to provide for the
increased population?
(A) 340
(B) 330
(C) 320
(D) 310
(E) 300

One way you can think of the problem is like this:

The wildlife preserve needs 10,000 acres of watering area for 3,000 rhinos. That means that there is about 10/3 acres of watering area/rhino.

With the increase of 10% => 3000(1.10) = 3300 rhinos

Number of acres of preserve needed = 3300(100) + 10/3 * (3300)

= 330,000 + 11,000 = 341,000 or about 340 thousand acres.

Choose A

You need 100 acres of grazing area per rhino. Therefore for 3000 rhinos you need 300,000 acres. In addition to this you need a total of 10,000 acres watering area. So total 310,000 acres.

If you need 310,000 acres for 3000 rhinos, how many acers will you need for 3300 rhinos?

Answer = (3300 * 310000)/ 3000 = 341,000 = apprx 340,000

Answer : A

3000 rhinos
amount of grazing= 100r
total=10000+100r
r=3300

A