By what percent is a 100-watt light bulb brighter than a 60-watt light bulb? Round to the nearest tenth.
40/60
= 2/3
= 2 ÷ 3
= 0.666667
0.666667 x 100 = 66.6667%
Answer: 66.7%
Is this correct?
100 / 60 = 2 * 5 * 10 / ( 2 * 3 * 10 ) =
5 / 3 = 1.6666666
1.6666 * 100 % = 166.66666 %
166.66666 % - 100 % = 66.66666 %
Correct answer.
why use divide?
Yes, that is correct. A 100-watt light bulb is approximately 66.7% brighter than a 60-watt light bulb.
The calculation you have provided is incorrect. To find the percentage difference in brightness between the two light bulbs, you need to first calculate the difference in watts, and then divide that by the original wattage of the 60-watt light bulb.
Let's go step by step:
1. Subtract the wattage of the 60-watt bulb from the wattage of the 100-watt bulb:
100 watts - 60 watts = 40 watts
2. Divide the difference by the original wattage of the 60-watt bulb and multiply by 100 to convert it into a percentage:
(40 watts / 60 watts) * 100 = 66.6667
3. Round the result to the nearest tenth:
Rounding 66.6667 to the nearest tenth gives us 66.7.
Therefore, the correct answer is that the 100-watt light bulb is approximately 66.7% brighter than the 60-watt light bulb.