Math Question?

Worded kind of weird:

A chartered bank is raising the interest rate on its Visa credit card from 7% to 8%. What will be the percent increase in the interest charges on a given balance?

Math Question?va loan

(8-7)/7=14.29%

Math Question? loan

( 7/8 ) * 100 %|||I tried some samples first and then I generalized to an equation.

If the balance was $100, then at 7% the interest is $70.

If the balance was $100, then at 8% the interest is $80.

So you would pay $10 more interest. If you take the raise in interest and divide it by the original interest you get 10/70 which is 1/7 or .1428 or about 14%. When I did this same thing with other amounts I always get the answer of 1/7

Generalizing : Let A be the balance amount then to find the percent on increase (.08A -.07A)/.07A and this will give 1/7.