DS:
Susan flipped a fair coin N times. What fraction of the flips came up heads?
(1) N = 24
(2) The number of flips that came up tails was N .
[spoiler]OA - B
To determine the fraction of the flips that came up heads, we would normally need to know the number of heads and the number of flips. Statement (1) gives us only part of the picture, the number of flips ( N ), so it is insufficient. Eliminate (A) and (D).
Statement (2) tells us the number of flips that came up tails, as a fraction of N. The only other option besides tails is heads, so we know the fraction of flips that came up heads. The value of N is then irrelevant. Statement (2) is sufficient[/spoiler]
How would I calculate the fraction?
Susan flipped a fair coin N times. What fraction of the flips came up heads?
(1) N = 24
(2) The number of flips that came up tails was N .
[spoiler]OA - B
To determine the fraction of the flips that came up heads, we would normally need to know the number of heads and the number of flips. Statement (1) gives us only part of the picture, the number of flips ( N ), so it is insufficient. Eliminate (A) and (D).
Statement (2) tells us the number of flips that came up tails, as a fraction of N. The only other option besides tails is heads, so we know the fraction of flips that came up heads. The value of N is then irrelevant. Statement (2) is sufficient[/spoiler]
How would I calculate the fraction?
