The task is to generate the correct answer for a given math problem.
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Question: Problem: calculate the sum of first 60 natural numbers .

Answer: 1830


Question: Problem: if 1.5 cm of a pencil is purple , 0.5 cm of the remaining is black and the remaining 2 cm is blue , what is the total length of the pencil ?

Answer: 4 cm


Question: Problem: the average age of 10 men is increased by years when two of them whose ages are 21 years and 23 years are replaced by two new men . the average age of the two new men is

Answer:
3