Answer:
10 minutes?
Step-by-step explanation:
Sorry if it is incorrect but what I did was I found the average of 5 minutes and 15 minutes and got 10.
Here's my problem solving explanation:
(5 + 15) / 2 = 10
The second equation is correct. Nina initally had 17 marbles in her bag. Her mother placed m marbles into her bag. After counting, she now has 34 marbles. Part of this 34 marbles is already her initial 17 marbles. Therefore, 17 marbles initially + m unknown marbles = 34 marbles. The equation <span>17 + m = 34 is the answer.</span>