Tom is on a certain diet that requires him to limit the

On some days Tom takes in 2400 + 3(200) = 3000 calories, and on other days he takes in 2400 + 200 = 2600 calories.

Let s represent the number of days he splurges, and let n (for normal) represent the number of days he does not splurge.

We know that s + n = 10, and since we are solving for s, we can say that n = 10 – s.

The total number of calories is (3000s + 2600n). Substuting (10 - s) for g we can rewrite the total number of calories as 3000s + 2600(10 - s).

Total number of calories ÷ Total number of days = Average number of calories per day.

[3000s + 2600(10 - s)] ÷ 10 = 2720
3000s + 2600(10 - s) = 27,200 (multiply both sides by 10)
26000 + 3000s – 2600s = 27,200
400s = 1200
s = 3

Alternatively, we could have plugged in the answer choices to solve the problem. If Tom had 7 days of consuming 2600 calories, then he must have had 3 days in which he consumed 3000 calories. He would have consumed a total of 7(2600) + 3(3000) = 27,200 calories. 27,200/10 = 2720.

The correct answer is A.

A faster method would be

If tom had followed guidelines precisely on each day than the average would had been 2600 calories (2400 + 200) for 10 day period.

But the average was 2720 i.e 120 more per day over the 10 day period that comes up to 1200 (120 * 10) more for a 10 day period.

The splurge was 200 to 600 (3 times) on x days (to be determined) i.e. 400 (600 - 200) more per day.

So \(x = \frac{1200}{400} = 3\)

Ans A

Is it a 700 Level question on GMAT ?
Doesnt look like the one.

thanks
Lucky

Hi Lucky2783,

Test Takers tend to put a lot of importance on the perceived "level" of a question, when that's actually something of a waste of time. Instead, you should evaluate whether the question is "gettable" or not. To that end, regardless of the difficulty level, if you make a silly/little mistake on a "gettable" question and get it wrong, then THAT is the issue that you need to focus on (and fix). Most questions on the Official GMAT are actually pretty straight-forward. Some of them are 'wordy' and in some cases the information given is not provided in the most useful "order", but if you want that high score, then you have to minimize (or ultimately eliminate) the little mistakes. The real "tough" part is that you have to perform at this level for 4 hours, which is something that most Test Takers have trouble with.

This prompt is wordy, but it's based on simple arithmetic and the Average Formula. As such, it probably doesn't feel that "hard" to you - if that's true, then great - don't worry about what "level" it is. Just get it correct in the most efficient way possible.

GMAT assassins aren't born, they're made,
Rich

On normal days, Tom takes 2400 + 200 = 2600 calories.
When he splurges, Tom takes 2400 + 200(3) = 3000 calories.

Instead of forming equations, let us go by options.

Option A: If he splurges on 3 days then his calorie intake for 10 day period = 3000(3) + 2600(7) = 27200
Hence average = 2720.
Hence option A is correct.

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Use the scale method:
The number of calories taken on a normal day = 2400 + 200 = AN.
Number of calories taken on a splurge day = 2400 + 3*200 = 3000 = AS

wN/wS = (AS - Aavg)/(Aavg - AN) = (3000 - 2720)/(2720 - 2600) = 280/120 = 7/3

So on 7 days, he consumed normal calories and he splurged on 3 days.

Answer (A)

For more on scale method, check: https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2011/03 ... -averages/

For Regular day Average calories = 2400+200 = 2600
For a Splurge day Average calories = 2400+600 = 3000

Average of calories for a mix of a number of Regular days and a number of Splurge days for a period of 10 days = 2720.

- If we have equal number of Regular days (5 days) + Splurge days (5 days) resulting average calories will be = 2800

Since the combined average calories is 2720 we can conclude that we have more Regular days than Splurge days, thus eliminating options c, d and e. Picking option (B) the combined average calories is 2760.

2600*(6/10) +3000(4/10) = 2760


Thus, Eliminating option B the answer is A.

i feel like an idiot. Did anyone else perceive "three times" the recommended as 3 times 2600. In other words three times the whole days worth. I just thought they meant that the extra calories were coming from desserts and snacks. not that it was only the desserts and snacks that were tripled. UUUUUGghhh

Total calories taken in 10 days; 2720*10 = 27200

Prescribed calories in 10 days; (2400+200)*10 = 26000

Excess calories taken; 27200-26000 = 1200

Number of splurge days; 1200/200 = 6..... (B)

Sent from my SM-N920C using GMAT Club Forum mobile app

we can solve it with 2 equations:
x+y=10
(2400+200)*x+(2400+200*3)y=27200
y is 3
answer is A

Hi All,

This question can be solved by TESTing THE ANSWERS instead of doing lots of calculations. Here's how:

We're told that the average for 10 days was 2720 calories, so the total number of calories is 2720 x 10 = 27,200

We're told that...
on a normal day, Tom eats 2400 + 200 calories = 2600 calories
on a splurge day, Tom easts 2400 + 600 calories = 3000 calories

We're asked for the number of splurge days.

Let's TEST THE ANSWERS…

Answer B = 4.
4 splurge days = 4 x 3000 = 12,000
6 normal days = 6 x 2600 = 15,600
Total Calories = 27,600
This is TOO MANY CALORIES (we're supposed to have 27,200), so this answer has TOO MANY splurge days.

The only answer that would give us fewer calories is answer . This must be the correct answer.

GMAT assassins aren't born, they're made,
Rich

We can let n = the number of days he splurges. Notice that on each of these n days, the total calorie intake 2400 + 3 x 200 = 3000. For each of the 10 - n days he doesn’t splurge, the total calorie intake is 2400 + 200 = 2600. Therefore, we can create the equation:

3000n + 2600(10 - n) = 2720 x 10

30n + 26(10 - n) = 272

30n + 260 - 26n = 272

4n = 12

n = 3

Answer: A

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