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This Lesson (EXAMPLES - Percentage Increase) was created by by longjonsilver(2297)
  About longjonsilver: I have a new job in September, teaching
EXAMPLE1: A student got 16 questions correct in a test. After re-sitting the same exam, he got 37.5% more questions correct. How many questions is this?
solution: 1.375 * 16 = 22 EXAMPLE2: The efficiency of an engine was given a score of 0.65. After applying some better lubricant, its efficiency increased by 22%. What is the new efficiency? solution: 1.22 * 0.65 = 0.793 EXAMPLE3: An athlete threw a javelin 55.12m this week, which was a 6% increase on his throw last week. What was the distance he threw last week? solution: this is slightly different, as we know the "answer" but not the original. The solution is still the same though: 1.06 * x = 55.12 so, x = 55.12/1.06 x=52m This is the trickiest type of question you will get with percentages. The secret is NOT to find 6% of 55.12 and then subtract it. That is definitely not correct: the percentage comes from the ORIGINAL, not the final value...ALWAYS!. This lesson has been accessed 11507 times. |
