Last visit was: 14 Jul 2025, 21:28 It is currently 14 Jul 2025, 21:28
Close
GMAT 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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bismuth83
User avatar
DI Forum Moderator
Joined: 15 Sep 2024
Last visit: 14 Jul 2025
Posts: 724
Own Kudos:
2,042
 [18]
Given Kudos: 441
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 724
Kudos: 2,042
 [18]
2
Kudos
Add Kudos
16
Bookmarks
Bookmark this Post
User avatar
Vi06
Joined: 23 Sep 2024
Last visit: 29 Mar 2025
Posts: 12
Own Kudos:
16
 [1]
Given Kudos: 22
Posts: 12
Kudos: 16
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
Bismuth83
User avatar
DI Forum Moderator
Joined: 15 Sep 2024
Last visit: 14 Jul 2025
Posts: 724
Own Kudos:
2,042
 [1]
Given Kudos: 441
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 724
Kudos: 2,042
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
Sandigaru
Joined: 17 Apr 2022
Last visit: 14 May 2025
Posts: 9
Own Kudos:
Given Kudos: 88
Location: India
Posts: 9
Kudos: 6
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello Bismuth,


Please clarify , it has been stated that 2 elves or 1 santa can carry atmost 20 gifts or 15 gifts respectively, if I'm not wrong then how you are able arrive at 30 gifts for 2 town in 1st hour only and distributing rest for 1st & 2nd town with balance, because if 2nd town to be provided with 3 gifts means it requires two visits and if two visits are completed then only one visit can be made to either of 1st or 3rd town, please clarify or else simultaneous means that you can visit any number of towns and can get back that counts as one trip.
Bismuth83
1. Let’s split the problem into 2 parts.

2. Part 1: finding \(T_1\). Santa and 5 of his elves can deliver at most \(15 + 10 * 5 = 65\) presents per hour. \(\frac{210}{65} \approx 3.23 > 3\). So, in theory, 4 hours is the least. Now, let’s build an example.

Hours1234567
00000000
115 (+15)30 (+10 * 3)20 (+10 * 2)0000
230 (+15)302030 (+10 * 3)20 (+10 * 2)00
3303030 (+10+0)302030 (+10 * 3)15 (+15)
43030303030 (+10+0)3030 (+15)

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

3. Part 2: finding \(T_2\). 5 of Santa’s elves can deliver at most \(10 * 5 = 50\). \(\frac{200}{50}\) = 4. So, in theory, 4 hours is the least. However, this is under the assumption that each elf can deliver 10 presents each hour. This is impossible since you will have a town with 20 presents delivered and sending at least 2 elves will waste the possibility of giving 10 more. Now, let’s build an example for 5 hours.

Hours1234567
00000000
130 (+10 * 3) 20 (+10 * 2)00000
2302030 (+10 * 3) 20 (+10 * 2)000
33020302030 (+10 * 3) 20 (+10 * 2)0
43030 (+10+0)3020302030 (+10 * 3)
530303030 (+10+0)3030 (+10+0)30

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

4. Our answer will be: \(T_1\) - 4 and \(T_2\) - 5.
User avatar
Sandigaru
Joined: 17 Apr 2022
Last visit: 14 May 2025
Posts: 9
Own Kudos:
Given Kudos: 88
Location: India
Posts: 9
Kudos: 6
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello, please clarify whether simultaneous means one can visit any number of town in one visit.
Bismuth83
1. Let’s split the problem into 2 parts.

2. Part 1: finding \(T_1\). Santa and 5 of his elves can deliver at most \(15 + 10 * 5 = 65\) presents per hour. \(\frac{210}{65} \approx 3.23 > 3\). So, in theory, 4 hours is the least. Now, let’s build an example.

Hours1234567
00000000
115 (+15)30 (+10 * 3)20 (+10 * 2)0000
230 (+15)302030 (+10 * 3)20 (+10 * 2)00
3303030 (+10+0)302030 (+10 * 3)15 (+15)
43030303030 (+10+0)3030 (+15)

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

3. Part 2: finding \(T_2\). 5 of Santa’s elves can deliver at most \(10 * 5 = 50\). \(\frac{200}{50}\) = 4. So, in theory, 4 hours is the least. However, this is under the assumption that each elf can deliver 10 presents each hour. This is impossible since you will have a town with 20 presents delivered and sending at least 2 elves will waste the possibility of giving 10 more. Now, let’s build an example for 5 hours.

Hours1234567
00000000
130 (+10 * 3) 20 (+10 * 2)00000
2302030 (+10 * 3) 20 (+10 * 2)000
33020302030 (+10 * 3) 20 (+10 * 2)0
43030 (+10+0)3020302030 (+10 * 3)
530303030 (+10+0)3030 (+10+0)30

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

4. Our answer will be: \(T_1\) - 4 and \(T_2\) - 5.
User avatar
bb
User avatar
Founder
Joined: 04 Dec 2002
Last visit: 14 Jul 2025
Posts: 41,097
Own Kudos:
Given Kudos: 23,430
Location: United States (WA)
GMAT 1: 750 Q49 V42
GPA: 3
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
GMAT 1: 750 Q49 V42
Posts: 41,097
Kudos: 80,207
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel - do you think it is too hard?
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Jul 2025
Posts: 102,570
Own Kudos:
Given Kudos: 98,182
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,570
Kudos: 741,437
Kudos
Add Kudos
Bookmarks
Bookmark this Post
bb
Bunuel - do you think it is too hard?
Yes, I’d say so. The wording is too complicated.
User avatar
Bismuth83
User avatar
DI Forum Moderator
Joined: 15 Sep 2024
Last visit: 14 Jul 2025
Posts: 724
Own Kudos:
Given Kudos: 441
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 724
Kudos: 2,042
Kudos
Add Kudos
Bookmarks
Bookmark this Post
For clarification, simultaneous means that the group (however split) can visit how many towns they want. However, each individual can only visit 1 town per hour. So, Santa can visit 1 town, Elf #1 can visit 1 town, etc. but these town don't have to be the same.

I hope that made sense!
Sandigaru
Hello, please clarify whether simultaneous means one can visit any number of town in one visit.
Bismuth83
1. Let’s split the problem into 2 parts.

2. Part 1: finding \(T_1\). Santa and 5 of his elves can deliver at most \(15 + 10 * 5 = 65\) presents per hour. \(\frac{210}{65} \approx 3.23 > 3\). So, in theory, 4 hours is the least. Now, let’s build an example.

Hours1234567
00000000
115 (+15)30 (+10 * 3)20 (+10 * 2)0000
230 (+15)302030 (+10 * 3)20 (+10 * 2)00
3303030 (+10+0)302030 (+10 * 3)15 (+15)
43030303030 (+10+0)3030 (+15)

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

3. Part 2: finding \(T_2\). 5 of Santa’s elves can deliver at most \(10 * 5 = 50\). \(\frac{200}{50}\) = 4. So, in theory, 4 hours is the least. However, this is under the assumption that each elf can deliver 10 presents each hour. This is impossible since you will have a town with 20 presents delivered and sending at least 2 elves will waste the possibility of giving 10 more. Now, let’s build an example for 5 hours.

Hours1234567
00000000
130 (+10 * 3) 20 (+10 * 2)00000
2302030 (+10 * 3) 20 (+10 * 2)000
33020302030 (+10 * 3) 20 (+10 * 2)0
43030 (+10+0)3020302030 (+10 * 3)
530303030 (+10+0)3030 (+10+0)30

Note: +15 - Santa arrived, +10 * 3 - 3 elves delivered maximum, +10 * 2 - 2 elves delivered maximum, +10+0 - 1 elf delivered 10 while the other was with them (since at least 2 must be on a trip).

4. Our answer will be: \(T_1\) - 4 and \(T_2\) - 5.
Moderator:
Math Expert
102570 posts