If we strictly follow the operations order via the PEMDAS initialism then the answer is indeed 15, as we always multiply first before dividing. I get why Seoyeon thought that was the answer. Smartphone/online calculators however give 0 as the answer. They are actually following a slightly more complex system which still uses the same PEMDAS idea but with an added condition of left to right precedence for equal priority operations, those being mutiplication/division and addition/substraction. So that's why 0 is the correct answer, as you would divide first before you multiply in this equation.

This is why parents shoulsnt help their children with their schoolwork Edit: following the order of operations the correct answer is actually 15.... The prompter actually got it wrong and Seoyeon was right.... Nvm, always listen to mom

저거 답이 틀린 거임... 결론은 문제가 성립 안 함.... 문제 자체가 틀려서 답이 없다가 정답