英數!!!急!

3) Venus borrows $20000 from a bank. It CHARGES simple interest at an interest rate 6.5% p.a. Whan she returns the money to the bank, besides the sum of money she has borrowed, she needs to pay $1950 to the bank too. How long does Venus borrow the money from the bank?


Let y be the no. of years she had borrowed,

20000+(20,000 x 0.065n)=20000+1950
20,000 x 0.065n=1950
n=1950 / (20000 x 0.065)
n=1.5

Therefore she borrowed the money for 1.5 years

2007-05-15 20:51:41 補充：
打錯左... n 即 y

20000 x 6.5% x years that Venus borrows the money+20000=20000+1950
years that Venus borrows the money=1950÷(20000 x 0.065)
=1.5years
=18 months