Question:
At the market, 5 light bulbs cost $9. How much do 7 light bulbs cost?
Answer:
Cost of 7 bulbs is $ 12.6
Solution:
Given that,
5 light bulbs cost $ 9
Find the cost of 1 bulb
Cost of 1 bulb is found by dividing the cost of 5 bulbs by 5
[tex]cost\ of\ 1\ bulb = \frac{\text{cost of 5 bulbs}}{5}\\\\cost\ of\ 1\ bulb = \frac{9}{5}\\\\cost\ of\ 1\ bulb = 1.8[/tex]
Thus cost of 1 bulb is $ 1.8
[tex]cost\ of\ 7\ bulbs = 7 \times \text{cost of 1 bulb }\\\\cost\ of\ 7\ bulbs = 7 \times 1.8\\\\cost\ of\ 7\ bulbs = 12.6[/tex]
Thus cost of 7 bulbs is $ 12.6
