Answer:
To determine the possible number of black marbles in the bag, we need to find a combination that satisfies the given conditions: the total weight of the marbles is less than 45 grams.
Let's analyze the options:
(A) If there are 4 black marbles, the total weight would be 4 * 3 = 12 grams, which is less than 45 grams.
(B) If there are 5 black marbles, the total weight would be 5 * 3 = 15 grams, which is less than 45 grams.
(C) If there are 6 black marbles, the total weight would be 6 * 3 = 18 grams, which is less than 45 grams.
(D) If there are 7 black marbles, the total weight would be 7 * 3 = 21 grams, which is less than 45 grams.
Based on the given conditions, options (A), (B), (C), and (D) are all valid possibilities for the number of black marbles in the bag.
Therefore, the correct answer is:
(A) 4
(B) 5
(C) 6
(D) 7
Step-by-step explanation: