GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jaya can flip 40 pancakes per minute, whereas Sally
[#permalink]
19 Aug 2017, 08:05
19 Aug 2017, 08:05
1
Expert Reply
1
Bookmarks
00:00
Question Stats:
82% (01:11) correct
17% (03:16) wrong based on 68 sessions
Hide Show timer Statistics
Jaya can flip 40 pancakes per minute, whereas Sally works at half Jaya's rate. How many minutes will it take the two of them to flip 150 pancakes, if Sally flips the first 30 by herself and is then joined by jaya for the remainder?
enter your value as a decimal
Show: :: OA
3.5
Re: Jaya can flip 40 pancakes per minute, whereas Sally
[#permalink]
30 Sep 2017, 05:52
30 Sep 2017, 05:52
1
If Jaya's rate is 1/40, Sally's rate is 1/20, double Jaya's rate.
Then, to compute the time spent in making 150 pancakes, we need Jaya and Sally's combined rate that is 1/60.
Thus, the answer is given by 30*1/20 + 120*1/60 = 7/2 = 3.5
Then, to compute the time spent in making 150 pancakes, we need Jaya and Sally's combined rate that is 1/60.
Thus, the answer is given by 30*1/20 + 120*1/60 = 7/2 = 3.5
Re: Jaya can flip 40 pancakes per minute, whereas Sally
[#permalink]
17 Apr 2019, 01:29
17 Apr 2019, 01:29
4
Simple logic can save time here instead of using formulas or any long arithematic.
Jaya flips 40 in a min
Sally can flip 20 in a min
when sally flips first 30 pancakes she takes 1.5 mins. Now 120 remain to be flipped when jaya joins in. when both work for 1 min they together can flip 60 pancakes. 40 Jaya and 20 Sally. So they need 1 more min to flip 60 more. So in 2 mins they together flip 120 pancakes. Now Sally flips first 30 in 1.5 mins so total time they take is 3.5 mins
Jaya flips 40 in a min
Sally can flip 20 in a min
when sally flips first 30 pancakes she takes 1.5 mins. Now 120 remain to be flipped when jaya joins in. when both work for 1 min they together can flip 60 pancakes. 40 Jaya and 20 Sally. So they need 1 more min to flip 60 more. So in 2 mins they together flip 120 pancakes. Now Sally flips first 30 in 1.5 mins so total time they take is 3.5 mins
