algebra question interest rates.?

Question

Samantha lent her brother some money at 9% simple interest and her sister one-half as much money at 16% simple interest. If she recieved a total of 34 cents in interest, then how much did she lend to each one?

Answer 1

Assuming she lent the money for one full period of interest, you would solve like this:

let b be the amount she lent the brother...
b*9% + b*1/2*16% = 0.34
9%*b + 8%*b = .34
17%*b=.34
b=2.00

so she lent the brother $2.00 and the sister half as much or $1.00

Answer 2

Let x = amount loaned to her sister
Then 2x + amount loaned to brother
x(1.016) +2x(1.09) = .34
1.016X + 2.18x =.34 --> x = 0.0939
She laoaned 9.4 cents to her sister and 18.8 cents to her bro.

Answer 3

wow i hate algebra.
let x = brother
y = sis
you use Pert ( pe^(rt) )
i dont know how to explain it but, ill tell you the answer

75 cents and $1.50