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Question

A coffee shop has received two new samples: a 240-gram pack of drip coffee containing 124 milligrams of caffeine, and a 60-gram pack of espresso with 160 milligrams of caffeine. If a barista were to create a new 120-gram blend by mixing equal parts of drip coffee and espresso, how many milligrams of caffeine would the resulting drink contain?

A. 111
B. 121
C. 142
D. 191
E. 382

Show Answer

Official Answer

D

A. 111
B. 121
C. 142
D. 191
E. 382

Bunuel · Accepted Answer

Official Solution:

A coffee shop has received two new samples: a 240-gram pack of drip coffee containing 124 milligrams of caffeine, and a 60-gram pack of espresso with 160 milligrams of caffeine. If a barista were to create a new 120-gram blend by mixing equal parts of drip coffee and espresso, how many milligrams of caffeine would the resulting drink contain?

A. 111
B. 121
C. 142
D. 191
E. 382

Show Answer

Official Answer

D

A. 111
B. 121
C. 142
D. 191
E. 382

A new 120-gram blend will be composed of 50% drip coffee and 50% espresso, resulting in 60 grams of each type. In 60 grams of espresso, there are 160 mg of caffeine, while in 60 grams of drip coffee, there are 31 mg of caffeine (which is one-fourth of the original 124 mg in the 240-gram pack). Therefore, the new drink will contain a total of 191 mg of caffeine (31 mg from drip coffee plus 160 mg from espresso).

Answer: D

DJ1986 · Answer

I though that the hardest part of this question was just organizing the data provided.

coffee:caffeine
240g:124mg

Espresso:caffeine
 60g:160mg

50/50: 120g total
60g of espresso + 60g of coffee 
160mg from espresso + 31mg from coffee = 191

Shrey9 · Answer

Why is that when we take 50 % of espresso, the caffeine quantity remains same (160 mg), but when we take 50% of drip coffee, we divide the caffeine quantity by 4 ?

shouldn't it be 160mg --> 80 mg from espresso
and 124mg --> 62 mg from drip coffee..
giving us 142 (C) ?

but I am unable to understand that why 142 (c) will contain 180 gram coffee and not 120 gram

VeritasPrepErika · Answer

You're forgetting to take into account what  volume  of drip coffee will be in the new drink compared to the volume of the initial cup of drip coffee.

The new drink is 120g, half of which is espresso and half of which is drip coffee. This means that there are 60g of espresso and 60g of drip coffee in the new drink.

The question tells us that 60g of espresso (the exact amount we want!) has 160mg of caffeine. So we get 160mg of caffeine from the 60 g of espresso.

However, the question tells us that  240g  of drip coffee ( not  the amount we want!) has 124 mg of caffeine. We only have 60g of drip coffee in the new drink — 60g is 1/4 of 240g, so it 60g of drip coffee should have 1/4 the amount of caffeine in 240g of drip coffee. Thus, we should get 124 / 4 = 31mg of caffeine from the 60 g of drip coffee.

So we have 160 + 31 = 191mg of caffeine in total in the new drink.

Your clue here is that  there was information from the question stem that you weren't using : 240g never came into your calculations. When you find that there's information you aren't using, it's more likely that you're missing something than that the question gave you extraneous information — you should go back and see how you could incorporate this information into your math.

RenanBragion · Answer

I think this is a  high-quality  question and I agree with explanation.

palaknayyar · Answer

The question is pure logic...

If the new mixture is to contain 120 grams from both individual samples, naturally, it has to include all 60gram of espresso, therefore the mixture definitely will have 160 mg caffeine- this allows us to strike off A,B and C from the get-go because the mixture cannot have <160mgs of caffeine.

Now all that is left is finding out how much caffeine does 60gram (remaining 50% of the new mixture) of drip coffee contain. Can find this by simple math: (124mg/240 gram)*60 gram= 31 mg.

Hence 160+31= 191 mg.

Final Answer: D

Hope this helps

akhtolkhyn · Answer

I think this is a  high-quality  question and I agree with explanation.

Bunuel · Answer

I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.

Rakshit99 · Answer

Drip Coffee: 240 grams/124 milligrams to find how much 60 grams of caffeine it contains. Which is 60/31, which means 60 grams contain 31 milligrams of caffeine. 
Now it is already given that 60 grams of expresso contains 160 milligrams of caffeine. Therefore now add both 160+31=191 milligrams of caffeine.

phmahi1997 · Answer

I like the solution - it’s helpful. A high quality question as well!

ReenaM0 · Answer

I like the solution - it’s helpful.

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