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For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

How to use order of operation in 20 divide by 4 multiply 5 = 1

Which term describes the point where the perpendicular bisectors of the three sides of a triangle intersect?