Question 1161201
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The two arithmetic sequence have the term 1 in common.<br>
The common differences in the two sequences are 4 and 7.<br>
The sequence of terms that are common to both sequences will be an arithmetic sequence with a common difference of 28, which is the LCM of 4 and 7.<br>
So the second term common to both sequences is 1+28 = 29.<br>
The sum of the first three terms of the sequence of terms common to the two given sequences is 3 times the second term of the sequence.<br>
ANSWER: 3*29 = 87<br>