Problem Solving (PS) | Re: There is a sequence of r, t, s, 1, 4, 3, 8, 15, 26. Each number of the

This sequence is possible when r = -2, s = 5, t = -2 as r+s+t = 1.
To double check whether the numbers we have selected are correct,
we also have s + t + 1 = 4 to prove that the numbers chosen are correct.

Hence, it is clear thatOption A(r = -2) is our correct answer.
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