Search found 2512 matches


Re: After the yearly performance appraisal, Boogle, fired 25% of its senior software engineers. What percentage of emplo

The wording could be better, but if we start with T employees, 35% of whom are senior engineers, then we start with 0.35T = (7/20)T senior engineers. We know a quarter of these engineers are fired, so the number of engineers and the total number of employees both drop by (1/4)(0.35T) = (7/80)T. So n...


Re: At a certain hospital, 75% of the interns receive fewer than 6 hours of sleep and report feeling tired during their

80% of all interns receive less than 6 hours of sleep. 75% of all interns receive less than 6 hours of sleep and report feeling tired. So, subtracting, 5% of all interns receive less than 6 hours of sleep and do not report feeling tired. We then also have the remaining 20% of interns who get more th...


Re: In the figure to the right, is b > a?

I assume the picture is meant to display straight lines. The angles in a circle add to 360 degrees, so here 3a + 3b = 360, and a + b = 120. So if we know a, we can find b and certainly answer the question, so Statement 1 is sufficient. If a+b = 120 and a < 60, then b > 60 must be true, so from State...

by Ian Stewart

Wed Feb 12, 2020 5:24 am
Forum: Data Sufficiency
Topic: In the figure to the right, is b > a?
Replies: 1
Views: 153

Re: On the coordinate plane (6, 2) and (0, 6) are the endpoints of the diagonal of a square. What are the coordinates of

If you understand slopes well, you can answer the question without much algebra. Recall that perpendicular slopes are negative reciprocals. So if you travel, say, 5 units to the right and 2 units up along one line, then to travel the same distance along a perpendicular line, you would need to travel...


Re: Percent and Interest Problems

Samantha invests i1 dollars in bond X, which pays r1 percent simple interest annually, and she invests i2 dollars in bond Y, which pays r2 percent simple interest annually. After one year, will she have earned more interest, in dollars, from bond X than from bond Y? 1) \((r1)^2 > (r2)^2\) 2) The ra...

by Ian Stewart

Tue Feb 11, 2020 1:39 pm
Forum: Data Sufficiency
Topic: Percent and Interest Problems
Replies: 1
Views: 169

Re: Is the standard deviation of set Q equal to 0?

Economist GMAT Is the standard deviation of set Q equal to 0? 1) The average (arithmetic mean) of set Q is equal to the greatest number in Q. 2) The mean of the set Q is equal to the greatest number in Q. OA A I don't understand the question. First, in math, a "set" cannot contain repeated elements...

by Ian Stewart

Tue Feb 11, 2020 1:33 pm
Forum: Data Sufficiency
Topic: Is the standard deviation of set Q equal to 0?
Replies: 1
Views: 173

Re: At the start of 2015, Jane opened two new accounts – X and Y – to invest her total savings of $1000. She invested

Even if she invests the maximum Statement 1 allows, namely $300, at 8% interest, and the remaining $700 at 6%, the 8% account won't earn anywhere close to the interest earned by the 6% account, so Statement 1 is sufficient. Clearly the more she invests at 8%, the more interest she earns. So if we kn...


All of the students of Music High School are in the band, the orchestra, or both. 80 percent of the students are in only one group. There are 119 students in the band. If 50 percent of the students are in the band only, how many students are in the orchestra only? A. 30 B. 51 C. 60 D. 85 E. 11 OA i...

by Ian Stewart

Tue Sep 03, 2019 12:34 pm
Forum: Problem Solving
Topic: Arithmetic
Replies: 2
Views: 382

Someone driving at 60 mph for 2.5 hours will drive a total of (2.5)(60) = 150 miles. If that distance corresponds to 5 inches on the map, then the scale of the map is 5 inches per 150 miles, or 1 inch per 30 miles, so 1/30 is the answer. That's assuming he drove in a straight line, which is somethin...

by Ian Stewart

Tue Sep 03, 2019 12:25 pm
Forum: Problem Solving
Topic: Before leaving home for the town of Madison, Pete checks a
Replies: 2
Views: 264

A string of 5 different colored light bulbs is wired in such a way that if any two-consecutive light bulb fails, then entire string fails. If for each individual light bulb, the probability of not failing during time period T is 0.85, what is the probability that the string of light bulbs will fail...

by Ian Stewart

Fri Aug 30, 2019 7:40 am
Forum: Problem Solving
Topic: A string of 5 different colored light bulbs is wired in
Replies: 3
Views: 308

Statement 1 tells us the number is 30 greater than a multiple of 45, so it is 30 greater than a multiple of 5, and must be itself a multiple of 5. So the remainder will be zero when we divide the number by 5, and Statement 1 is sufficient. Using Statement 2, we know we get a remainder of 3 when we d...


Most of the information in the stem is irrelevant, so I'm not sure why it's there, but we have no information, even using both Statements, about the magenta cable, so we can't answer any question about the sum or average of all four of the cables. So the answer is E.

by Ian Stewart

Thu Aug 29, 2019 6:23 am
Forum: Data Sufficiency
Topic: An Internet supplier has 4 international cables. Each cable
Replies: 2
Views: 265

Statement 1 tells us that a is the cube root of some integer. Sometimes cube roots of integers are themselves integers, and sometimes not, so Statement 1 is not sufficient. Statement 2 tells us that the cube root of a is an integer, so a itself will be the cube of an integer, and must therefore be a...

by Ian Stewart

Tue Aug 27, 2019 9:03 am
Forum: Data Sufficiency
Topic: Is a an integer?
Replies: 2
Views: 271