Query about Question 9 from "(I'm Overwhelmed) Arithmetic Progress Quiz #6"

[user11892]

https://www.gregmat.com/quizzes/quiz/im-overwhelmed-arithmetic-progress-quiz-6 (Question 9)

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In the solution for this question it says the answer is 40. But on the actual quiz it says the answer is 0

[Leaderboard]

@user11892

solution for this question it says the answer is 40

Where?