Math CentralQuandaries & Queries


Subject: Answer to skill testing question
Name: Mike
Who are you: Other

This question was on a ballot. Is the right answer 36 or 1? 5+2-1X6=

Hi Mike.

The problem with these "skill testing questions" is that the company that makes them almost always has no skill!

You are right to ask, because usually such questions ignore basic grade 4 math: the rules of the order of operations. The mathematically correct answer is
5 + 2 - 1 x 6 = 1

but if you ignore the fact that multiplication must be done before addition or subtraction and just do it from left to right, you will get 36.

The reason, I think, they do this is that years ago when laws were enacted surrounding such "prizes", they had to make an easy question for people to solve and they made it a math question because calculators had been invented. So people used calculators, but early calculators didn't follow the order of operations because they weren't sophisticated enough in those years. So if you punched those numbers into an old calculator, you'd get 36 rather than 1.

It's a sad state of affairs that companies that make these tickets are either unable to do basic math operations or too arrogant to think they might be wrong and the rest of the world right about this.

If you talk to them, tell them to buy a new calculator.

Stephen La Rocque.>

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