The price of a cup of coffee was 2: 40 yesterday today it rose 265 find the percentage increase

N.B. I believe your question is saying that the price of a cup of coffee was $2.40 yesterday, and it rose to $2.65 today. Therefore, I will solve with these prices. 

The percent increase is 10.41666666% (The 6 is repeating.).

First, you find the difference, or increase, between the two prices.

New price - Old price = Increase

$2.65 - $2.40 = $0.25

The difference between the two prices is $0.25. To find the percent increase, you want to divide the original price ($2.40) from the increase ($0.25) and multiply by 100.

Increase ÷ Original Price × 100 = % increase

0.25 ÷ 2.40 × 100 = 10.41666666%

The percent increase is 10.41666666% (The 6 is repeating.).