How many times will the boat cross this river?

5 minus the skipper leave you with only 4 people per trip.... 4 divides by 25 is 6, remaining one person... That's approximately 7 times

The boat will cross the river 13 times, if all the people will cross to the same side and the pilot is not counted among the 25 people. The boat crosses the river twice per trip (going and coming), except the first trip that requires just one crossing (going alone) because the boat is on the same side with the people prior to the begining of the journey. The boat carries 4 passengers and the pilot per trip. The boat will need 7 trips to cross the 25 people. Each trip will have 5 people on the boat, except the 7th trip that will have 2 people on the boat.

The boat will cross the river 10 times, if all the people are crossing to the same side and the pilot is counted among the 25 people.

Hope they have life jacket?

Wawelexy:
5 minus the skipper leave you with only 4 people per trip.... 4 divides by 25 is 6, remaining one person... That's approximately 7 times

I doubt that answer

For every five person's ferried, the boat crosses the river twice except for the last trip. Technically there are 30 persons. Because the skipper has to journey with four people on every trip (maximum of five)
We should have 30/5 will be 6. But there are two crossings for each ferrying so that would be 6*2 which is twelve crossings.
But remember the boat does not need to return on the last trip so that will b 12-1 to adjust for this logic.

13 times...

immortalcrown:
14 times if all the people will cross to the same side and the pilot is not counted among the 25 people. The boat crosses the river twice per trip (going and coming). The boat carries 4 passengers and the pilot per trip. The boat will need 7 trips to cross the 25 people. Each trip will have 5 people on the boat, except the 7th trip that will have 2 people on the boat.

10 times if all the people are crossing to the same side and the pilot is counted among the 25 people.

focus on the question: all the people will need to cross the river, so if each boat trip carries 4 people, then it will take the boat 12 trips (6 trips back and forth) to carry 24 people, and thereafter only ONE more trip to carry the last person over the other side.

that would make it 13 trips, not 14...

ChristCee:
For every five person's ferried, the boat crosses the river twice except for the last trip. Technically there are 30 persons. Because the skipper has to journey with four people on every trip (maximum of five)
We should have 30/5 will be 6. But there are two crossings for each ferrying so that would be 6*2 which is twelve crossings.
But remember the boat does not need to return on the last trip so that will b 12-1 to adjust for this logic.

you mean 12 + 1...

4 persons dropped per trip
5 trips =20 persons
Boat crossing to & fro = 10 trips
Last trip carries remaining 5 persons

Total trips = 11 times 👍

GanagiBitrus:


4 persons dropped per trip
5 trips =20 persons
Boat crossing to & fro = 10 trips
Last crossing carries remaining 5 persons
Total crossing = 11 times 👍

so who drives the boat on the last crossing since you are bringing the remaining 5 people along (and not the boat skipper)?

MrBrownJay1:


so who drives the boat on the last crossing since you are bringing the remaining 5 people along (and not the boat skipper)?

The boat skipper is one of the 25persons.
The puzzle didn't say there is an extra person who is the skipper.

MrBrownJay1:
13 times... focus on the question: all the people will need to cross the river, so if each boat trip carries 4 people, then it will take the boat 12 trips (6 trips back and forth) to carry 24 people, and thereafter only ONE more trip to carry the last person over the other side.

that would make it 13 trips, not 14...

You are correct. But why telling me to focus on the question? Was I focusing on your head before?

immortalcrown:
You are correct. But why telling me to focus on the question? Was I focusing on your head before?

lol...

GanagiBitrus:

The boat skipper is one of the 25persons.
The puzzle didn't say there is an extra person who is the skipper.

it says: "a team of 25 people NEED TO BE FERRIED" (and not "need to cross" )...so someone has to ferry them across the river (aka the skipper of the boat).

if it was just 25 people and a boat then it would simply say:"25 people need to cross a river"

MrBrownJay1:


it says: "a team of 25 people NEED TO BE FERRIED" (and not "need to cross" )...so someone has to ferry them across the river (aka the skipper of the boat).

if it was just 25 people and a boat then it would simply say:"25 people need to cross a river"

How did you know there was a skipper available to do the ferrying? Did the puzzle state there was a skipper available?


Needs to be ferried BY A BOAT not
Needs to be ferried by a skipper.

GanagiBitrus:

How did you know there was a skipper available to do the ferrying? Did the puzzle state there was a skipper available?
Needs to be ferried BY A BOAT not
Needs to be ferried by a skipper.

it doesnt matter whether a skipper is available or not, they NEED TO BE FERRIED therefore someone has to ferry them across the river. its very simple to understand IMHO.

MrBrownJay1:
13 times...



focus on the question: all the people will need to cross the river, so if each boat trip carries 4 people, then it will take the boat 12 trips (6 trips back and forth) to carry 24 people, and thereafter only ONE more trip to carry the last person over the other side.

that would make it 13 trips, not 14...



you mean 12 + 1...

No. Let me break it down.
Trip one. Four people with the paddler.
Return trip. (Two trips)
Trip two. Four people with the paddler.
Return trip. (Four trips)
Trip three. Four people with the skipper.
Return trip. (Six trips)
Trip four. Four people with the skipper.
Return trip. (8 trips)
Tripe five. Four people with the skipper
+ Return trip (10 trips)
.
At this point we have ferried 20 people across with ten trips.
.
Trip six four people with the skipper (leaving one person behind)
Return trip for that person (twelve trips)
.
One last trip for that person and the skipper without return.
.
13 trips. You are right. I made a mistake in my maths.
.
I should have accounted for that 'constant' the skipper who goes on every return trip.
.
12+1 is correct.

immortalcrown:
The boat will cross the river 13 times, if all the people will cross to the same side and the pilot is not counted among the 25 people. The boat crosses the river twice per trip (going and coming), except the first trip that requires just one crossing (going alone) because the boat is on the same side with the people prior to the begining of the journey. The boat carries 4 passengers and the pilot per trip. The boat will need 7 trips to cross the 25 people. Each trip will have 5 people on the boat, except the 7th trip that will have 2 people on the boat.

The boat will cross the river 10 times, if all the people are crossing to the same side and the pilot is counted among the 25 people.

Your explanation doesn't really add up