HESI MCA II Practice Test

Adding fractions with different denominators requires rewriting each fraction so they share a common denominator, then adding the numerators. For 3/4 and 5/6, a convenient common denominator is 12. Convert: 3/4 becomes 9/12 (multiply top and bottom by 3), and 5/6 becomes 10/12 (multiply top and bottom by 2). Now add: 9 + 10 = 19, giving 19/12. This improper fraction is equivalent to 1 7/12 if you prefer a mixed number. The other options don’t come from correct conversion to a common denominator and addition.