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This Lesson (HOW TO - Percentage Increase) was created by by longjonsilver(2297)    : View Source, ShowAbout longjonsilver: I have a new job in September, teaching
Beyond the basics of percentages, a typical question would be along the lines of:
EXAMPLE: An item last year cost $450. If it increases this year by 15%, what is its new cost? Long-winded solution, with explanation is as follows... I shall find what 15% of 450 is and then add this onto 450. This will be the answer. So, (15/100) * 450 = 67.5 Therefore, the new cost is 450 + 67.50 = 517.50. Quick Solution (in one line): 1.15*450 = 517.50 The full explanation of this starts with the first solution from above, which is the original price plus the 15% of it: 450 + 0.15*450 ... NOTE the 0.15 (which is 15% in decimal form) This can be written as 1*450 + 0.15*450 (1+0.15)*450 1.15*450 = 517.50 The skill is reading the question and jumping to the last line. EXAMPLE: A golf club last year cost $80. Its price is increased by 6%. What is the new cost of the club? Well, 6% is 6/100 or 0.06 as a decimal, so 1 (the original) + the 0.06 will be the percentage increase: 1.06 * 80 = 84.8 Done! In summary Increase of 1%... multiply by 1.01 Increase of 2%... multiply by 1.02 Increase of 5%... multiply by 1.05 Increase of 10%... multiply by 1.10 Increase of 20%... multiply by 1.20 etc This lesson has been accessed 4074 times. |