A candy bar cost the store $0.79. The store wants a 65% mark up. What would the price of the candy bar be to have a 65% mark up?

answer:  

\boxed {\frac{1}{5}}  

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

solution-

60 *   \frac{1}{5}   = 12

90 * \frac{1}{5} = 18

75 * \frac{1}{5} = 15

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

hence, the answer would be \boxed {\frac{1}{5}}