Bunuel
At company X, do at least 40 percent of the workers over the age of 40 years have 401(k) accounts?
(1) At company X, 16 percent of the workers age 40 years and younger have 401(k) accounts and 29 percent of all workers at the company have 401(k) accounts.
(2) At company X, there are more workers age 40 years of age and younger than workers over the age of 40.
Let there be 'x' workers less than equal to 40 years of age, and let there be 'y' workers greater than 40 years of age. We need to know whether 0.4y or above have those accounts or not.
(1) So 16% of x, and 29% of (x+y) have those accounts. But what is the ratio of x:y? Without knowing the answer to that question, we cannot conclude the percentage of y that have those accounts. Not sufficient.
(2) Not sufficient clearly.
Combining the statements, we know that 16% of x and 29% of (x+y) have those accounts and x > y or x/y > 1 given.
Let there be a% of those y workers having these accounts. Using weighted average alligation method, ratio of x and y must be (a-29)/(29-16) or (a-29)/13. Since this ratio has to be greater than 1 (given), we can take:
(a-29)/13 > 1 or a-29 > 13 or a > 42.
So the % of y workers who have these accounts must be greater than 42%, which is greater than 40% definitely. sufficient.
Hence
C answer