## Tuesday, February 2, 2010

### Nhea's Ratio Scribepost, 2/2/10

7. A herd of 100 caribou was moved to a new location. The population increased by 10% the first year and then increased by 20% the second year.

a) Find the population after the second year.

First year - 100 / 10 = 10 = 10%

-100 + 10 = 110

Second year - 110 / 10 = 11 x 2 = 22 = 20%

-110 + 122 = 132
b) Explain why there was not a 30% increase in population over the two years

The increase was not by 30% because the 20% was worked in after the 10 percent was already placed, making it 132.

11. A student is awarded a \$1000 scholars
hip and places it in an account that pays 3% simple interest per year.

a) What is the total value of the scholarship
amount at the end of the second year?

First Year - 1000 / 10 = 100 / 10 = 10 x 3 =30 = 3 %
-1000 + 30 = \$1030

Second year -
1030 / 10 = 103 / 10 = 10.30 x 3 =30.90 = 3 %
- 1030 + 30.90 = \$1060.90

b) What is the single percent increase in value of the scholarship after two years?

(3 % = 30) + (3 % = 30.90) = 60.90 / 10 = 6.09% after two years