Quandaries and Queries


Who is asking: Other
Level: Middle

Please send me the equation(and explanation) for the solution for the following: What number decreased by 331/3% is 30?




Since 331/3% is one-third, 30 is two-thirds of the number you started with. Half of two-thirds is one-third and half of 30 is 15. Thus 15 is one-third of the number you started with. Three times 15 is 45 and three times one-third is one, hence the number you started with is 45.

Let's check. One-third of 45 is 15 and 45, decreased by 15 is 30.



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