0.074n = 74
multiply both sides by 1000 to make the process simpler
74n = 74000
divide both sides by 74
n = 1000
Sqrt 13 and 1.1919919991... are irrational, meaning that they can't be described in a fraction of one integer over another, like 1/3, 45/44 or 57/107, these numbers are rational. Most irrationals are known constants like e or π, endless non-repeating decimals, or roots of non-perfect numbers like 13, 7, 5 or 2.
The LCD (least common denominator) is the lowest number that both denominators (12 and 5) go into. The lowest number that both 5 and 12 go into is 60. The LCD of the two fractions is 60.
The answer is about 60ish. Hope this helped. :-)