1 .65 + 0.20(65) = 65 + 13 = 78 (65 - 60) / 65 = 5/65 = 0.0769 x 100 = 7.69 rounds to 7.7 % decrease compared to the 65 pizza's sold yesterday
2. I posted a file to help you on this question!
3. <span>Find principal by using the formula </span><span>I=P⋅i⋅t</span><span>, where </span>I<span> is interest, </span>P<span> is total principal, </span>i<span> is rate of interest per year, and </span>t<span> is total time in years. </span> So basically your answer is 600.