Final answer:
Kala's rate of typing is 4 words per minute.
Step-by-step explanation:
To calculate the rate in words per minute, we need to divide the total number of words by the time taken. In this case, Kala typed 28 words in 7 minutes. To find the number of words per minute, we divide 28 by 7, which gives us a rate of 4 words per minute.
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