James can eat 25 marshmallows is 20 minutes. Dylan can eat 25 in one

Question

James can eat 25 marshmallows is 20 minutes. Dylan can eat 25 in one hour. In how much time will the two eat 150 marshmallows?

A. 40 minutes.
B. 1 hour and 30 minutes.
C. 1 hour.
D. 1 hour and 40 minutes.
E. 2 hours and 15 minutes.

shashanksagar · Answer

B? 150 /(25×3 + 25) hrs

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raven09 · Answer

Rate =Output/Time
James Rate=25/20=5/4
Dylan Rate=25/60=5/12
Combined rate = 5/4+5/12= 20/12
CombinedRate*CombinedTime= CombinedOutput
20/12*t=150
t=90 mins => 1 hr 30 min

LXVE · Answer

James eats 25 marshmallows in 20 min so he eats 75 per hr. 
Dylan eats 25 per hr.
Together they would eat 100 per hr. So 150 would take 1.5 hrs

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ShashankDave · Answer

+1 for (B).
But the OA is C.  Bunuel . Is something wrong?

Bunuel · Answer

Edited the OA. Thank you.

law258 · Answer

Simple.

James's rate = 5/4
Dylan's Rate = 5/12

5/4 + 5/12 = 150/x
20/12 = 150/x
x = 90 min (or 1.5 hrs)

B

Reet07 · Answer

James= 25 marshmallows in 20 min 
Daylan = 25 marshmallows in 60 min

therefore, James can have 75 marshmallows in 60 min.

Total in 1 hour both can have 100 (75+25) Marshmallows.
for 150 Marshmallows, 
1 hour ( 100 marshmallows) + 30 minutes ( 50 marshmallows )

Answer 1 hour 30 mins. 
B

AkshdeepS · Answer

James can eat 25 marshmallows is 20 minutes

Or James can eat 3 * 25 = 75 marshmallows in 20 * 3 = 60 minutes or 1 hour

Dylan can eat 25 marshmallows in 1 hour

Combined rate = 100 per hour

So to eat 150 marshmallows it takes 1:30 hours

(B)

ScottTargetTestPrep · Answer

The combined rate, in marshmallows per minute, of James and Dylan is 25/20 + 25/60 = 5/4 + 5/12 = 15/12 + 5/12 = 20/12 = 5/3.

To eat 150 marshmallows, it will take them 150/(5/3) = (150 x 3)/5 = 30 x 3 = 90 minutes = 1 hour and 30 minutes.

Alternate solution:

Since James can eat 25 marshmallows in 20 minutes, he can eat three times as many in an hour. Thus he can eat 75 marshmallows in one hour. Therefore, the combined rate, in marshmallows per hour, of James and Dylan is 75 + 25 = 100.

So it takes them 150/100 = 1.5 hours = 1 hour and 30 minutes, to eat 150 marshmallows.

Answer: B

bumpbot · Answer

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James can eat 25 marshmallows is 20 minutes. Dylan can eat 25 in one

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