Percent

• Percent is a measure of parts per hundred.
• Percent is usually expressed between 0% = .0 and 100% = 1.0
• Converting a fraction to percent
  • Divide the fraction out.
  • Multiply the result by 100
  • Add the % sign.
• Examples : 7-22
• Percent change = (new amount - old amount)/ old amount
• Percent markup = (selling price - dealer cost)/ dealer cost
• Problem 44, 56, 60

Personal Loans and Simple Interest

• Simple interest. Borrow money, pay it back plus interest in a lump sum.
• i = prt
• In simple interest loans, a year has 360 days, a month has 30 days and a year has 12 months.
• r, unless otherwise stated, is in annual percentage rate.
• Make sure that p and t are in the same terms.
  • Problems 10 - 18
• A discount note the principle plus interest are stated up front.
• See problem 28.

  i = prt
  a) i = 2500*5/12*.08 = $83.33
  b) 2500-83.33 = 2416.67
  c) i = prt
     i = 83.33, p = 2416.67, t = 5/12
     r = i/pt
     r = 83.33/ (2416.67*5/12)  = 0.0827 = 8.3%
  	

Homework

• Page 653, 7 through 67 odd.
• Page 665, 9 through 32 odd.