Quote:
d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?
(1) If d were rounded to the nearest hundredth, the result would be 0.44.
(2) If d were rounded to the nearest thousandth, the result would be 0.436.
We are given that t denotes the thousandths digit of 0.43t7. We need to determine the value of t.
Statement One Alone:If d were rounded to the nearest hundredth, the result would be 0.44.
Using the information in statement one, t could be different values. For example, t could be 5 (so that d would be 0.4357) or t could be 6 (so that d would be 0.4367). Similarly, t could also be 7, 8, or 9. Notice in any of these cases, d rounds up to 0.44.
Thus, statement one is not enough information to answer the question. We can eliminate answer choices A and D.
Statement Two Alone:If d were rounded to the nearest thousandth, the result would be 0.436.
Using the information from statement two, d must be 0.4357. Because of the “7” in the ten-thousandths digit, we see that 0.43t7 will only round up to 0.436. Thus, t can only be the value 5. Any other value of t will not round d to 0.436 when rounded to the nearest thousandth. Statement two is sufficient to answer the question.
The answer is B.