Data Sufficiency

Fifty percent of the articles in a certain magazine are written by staff members. Sixty percent of the articles are on current affairs. If 75 percent of the articles on current affairs are written by staff members with more than 5 years experience of journalism, how many of the articles on current affairs are written by staff members with more than 5 years experience?

1. 20 articles are written by staff members.
2. Of the articles on topics other than current affairs, 50 percent are by staff members with less than 5 years experience.

(1) TOT is the total number of articles written by staff members: (0.50) TOT = 20 => TOT = 40. (0.60) 40 = 24 = articles on current affairs. (0.75) 24 = 18 = articles on current affairs written by staff members with more than 5 ys experience. SUFF.

(2) We have only percentages but NOT numbers, so this is INSUFF.

The correct answer is A.

harsh.champ wrote:Fifty percent of the articles in a certain magazine are written by staff members. Sixty percent of the articles are on current affairs. If 75 percent of the articles on current affairs are written by staff members with more than 5 years experience of journalism, how many of the articles on current affairs are written by staff members with more than 5 years experience?

1. 20 articles are written by staff members.
2. Of the articles on topics other than current affairs, 50 percent are by staff members with less than 5 years experience.

Fifty percent of the articles in a certain magazine are written by staff members. Sixty percent of the articles are on current affairs. If 75 percent of the articles on current affairs are written by staff members with more than 5 years experience of journalism.

So total article written by staff members with more than 5 years experience of journalism= .5 x .6 x .75 = 0.225 = 22.5 % of the total.

St.1 : 20 articles are written by staff members. i.e. there are total 40 articles (since fifty percent of the articles are written by staff members). so .225x 40 = 9 ===========sufficient
St.2 : surely in this statement we can easily calculate that what percentage each contribute in different section.
but we don't have any data for calculating exact values
So I go with A