Joanie has 15 hair ribbons. She has 7 less hair ribbons than her friend, Sara. Which equation can be used to determine the number of hair ribbons Sara has, s?
S-7 = 15
7 - S =15
7s = 15
S + 7 = 15

In a week, a light bulb factory produces 12,500 light bulbs. the ratio of light emitting diodes (led bulbs) to compact fluorescent lamps (cfl bulbs) is 2: 3. of the led bulbs produced, 3% were defective. how many led bulbs were not defective? a) 150b) 2,425c) 4,850d) 7,275