exam :: next week please help

[anindita.dc]

x and y each represent single digits in the decimal 4.3xy8. When the decimal is rounded to the nearest hundredth the result is 4.36

col A col b
x 5

how to solve that.
4.3xy8 = 4.36

So if 4.36 rounded up in nearest number then that number must be something 4.35**8. Thats why nearest round up is 4.36. So is it x equal to 5.


i need ans please help.

[tommywallach]

Hey Anindita,

In a question like this, you have to be careful about rounding. Remember that you cannot double round. In other words, you must say that 4.346, when rounded to the nearest tenth, is 4.3. If you're rounding to the nearest tenth, you simply look at the NEXT digit (hundreds), and if it's 4 or less, you round down. 5 or more, you round up. In this case it's 4, so we round down, to 4.3.

What you CANNOT do is this: say that 4.346, when rounded to the nearest HUNDREDTH would be 4.35, and thus, when THAT is rounded to the nearest tenth, you get 4.4 (because now the hundredths digit is a 5). You can only round ONE time, not twice.

So if we have 4.3xy8 = 4.36, the x digit could be 5, and the y digit could be 5-9, which would cause us to round the x digit up to 6, or else the x digit could be 6 and the y digit could be 0-4, causing us to round down to 6. We ENTIRELY ignore the 8 here (the ten-thousandths digit), because when you round to a digit in a decimal, you only use the VERY NEXT digit to inform it. Do not round multiple times.

Hope that helps!

-t

[mkamony]

After review, answer is D

4.3xy8 rounded to the nearest 100th is 4.36

so x=y=5, you get 4.36

x=6, y= 4, 4.36

[galtgallery]

To clarify on this question, then it seems the accurate answer is:

it cannot be determined from the information given


x and y could have a variety of values, and it cannot be determined with certainty what they will be.

[tommywallach]

Hey All,

Yes, the answer is D. Apologies if that wasn't clear. However, it is not SIMPLY because we found multiple values for x. Remember, this is about a quantitative comparison.

We found two possible values for x --> 5 or 6. We are comparing that to the other column, which has 5.

If x = 5, then the two columns are equal. If x = 6, then Column A is bigger. That's why the answer is D.

If the two values we found for x were 3 and 4, the answer would be B. If the two values we found for x were 7 and 8, the answer would be A. We got D here because we have one x value that is EQUAL to the value in the other column, and one that is LARGER than the value in the other column.

Hope that makes sense!

-t