Whats 12 divided by 1/3?

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Answer 1 · 2015-09-10T02:44:52

$12 -: 1/3 = 12 * 3/1 = 36$

In general, you can divide by a rational expression by multiplying by the same expression with numerator and denominator swapped. That is:

$a -: b/c = a * c/b$

For example:

$3/5 -: 7/5 = 3/5 * 5/7 = (3*color(red)(cancel(color(black)(5)))) / (color(red)(cancel(color(black)(5)))*7) = 3/7$

or even:

$(x + 1) / (x + 2) -: (x + 3) / (x + 4) = (x+1) / (x+2) * (x+4)/(x+3)$

Answer 2 · 2015-09-10T02:47:10

36

$12 -: 1/3 = 12 * 3 = 36$