5lb. 3rd ed. Ch11 Q18 - Why is the answer not D?

The question is x is a digit in the decimal 12.15x9, which, if rounded to the nearest hundredth, would equal 12.16. Quantity A = x, Quantity B =4.

The answer sheet says A as we already know it has to be greater than or equal to 5. But there is another way to get 12.16 is if we at first round the ten thousandths position, 9 then, x can be 4 too and it becomes 5 after rounding. And in the next step, thousandths position is rounded, leaving us 12.16. Hence, shouldn’t the answer be D?

The question is stating that when rounding to the nearest hundreth, the number is 12.16. Why would you then try to round to the nearest ten thousandth? Not sure I understand what your question is. Are you suggesting to first round the number to the nearest ten thousandth, and then the resulting number rounding it to the nearest thousandth, and then rounding it again, but now to the nearest hundredth?

yes, that’s what I was suggesting and this is why I think, as there are two answers, final answer is D. sorry for the late reply, didn’t get any push notifications.