A fraction is written in terms of two parts: the number on top is called the numerator and the number on the bottom is called the denominator. We can use the division method to solve this question. To get a decimal, simply divide the numerator 141 by the denominator 42:
141 (numerator) ÷ 42 (denominator) = 3.36
As a result, you get 3.36 as your answer when you convert 3 15/42 (or 141/42) to a decimal.