2, 6, 15, 28, ?, 78Series teasers are where you try to complete the sequence of a series of letters, numbers or objects.
Find the missing number in the following series:
2, 6, 15, 28, ?, 78
First take 1 multiplied by the first prime number (2), 2 * second prime number (3), 3 * third prime number (5) and so on.
Therefore the answer is 5 * 11 = 55.
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