Sum indicates addition - you must add these fractions together. To add fractions, they must have a common denominator. The least common multiple of 6, 3, and 4 is 12. Multiply the fractions as follows to get a common denominator of 12.
1/6 × 2/2 = 2/12
2/3 × 4/4 = 8/12
1/4 × 3/3 = 3/12
Add the fractions (add their numerators).
2/12 + 8/12 + 3/12 = 13/12
Answer:
[tex] \frac{13}{12} [/tex] or [tex] 1\frac{1}{12} [/tex]