Final answer:
Gabriel originally had 72 comic books in his collection. He kept 1/3 of his collection and after receiving 6 more comics for Christmas, he had 30 comics in total. The correct answer is Option 4: 72.
Step-by-step explanation:
The student is asking a math problem related to fractions and basic arithmetic operations. To find the original number of comic books in Gabriel's collection, let's use the information provided. Gabriel kept 1/3 of his collection and then added 6 more comics to have a total of 30. Therefore, the 1/3 of the collection plus the 6 comics equals 30.
Let's represent the original number of comics as 'x'. According to the problem:
½ (1/3 * x) + 6 = 30
Multiplying both sides of the equation by 3 to eliminate the fraction gives us:
x + 18 = 90
Now, subtract 18 from both sides:
x = 90 - 18
x = 72
Therefore, Gabriel originally had 72 comic books in his collection before he sold some to pay for Christmas gifts. This corresponds to Option 4: 72.