MathDB
Problem B3

Source: 2019 Malaysia OMK

August 21, 2019
arithmetic sequenceArithmetic Progressionalgebra

Problem Statement

An arithmetic sequence of five terms is considered goodgood if it contains 19 and 20. For example, 18.5,19.0,19.5,20.0,20.518.5,19.0,19.5,20.0,20.5 is a goodgood sequence. For every goodgood sequence, the sum of its terms is totalled. What is the total sum of all goodgood sequences?
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