Final answer:
To calculate the speech rate in words per minute, divide the number of words spoken by the time taken in minutes. In this case, the child spoke 50 words in 30 seconds, so the speech rate is 100 words per minute.
Step-by-step explanation:
To calculate the speech rate in words per minute, divide the number of words spoken by the time taken in minutes.
Given that the child spoke 50 words in 30 seconds, we need to convert the time to minutes. Since there are 60 seconds in a minute, divide 30 seconds by 60 to get 0.5 minutes.
Now, divide the number of words (50) by the time in minutes (0.5):
Speech rate = 50 words / 0.5 minutes = 100 words per minute