If 2 people are digging a hole in 5 hours then how many people does it take to dig a hole in 5 minutes?
For Grade 5 Math
I always find these questions super tricky.
I am going to do it without algebra. :)
2 people take 5hours
If you have more people, it would take less time - that makes sense doesn't it?
so
2*5people take 5 ÷ 5 hours
10 people take 1 hour
now 5 minutes is 5/60=1/12 of an hour
10*12 people would take 1/12 hours
120 people will take 5 minutes
Of course they would all get in each others way so I do not think it would really work that way. LOL
This is known as a "see-saw" problem.....that is, the product of one side of the equation must equal the product of the other side
So, two people dig a hole in 5 hrs. = 300 minutes
So
2 x 300 = N * 5 where N is the number of people we're looking for
600 = N * 5 divide by 5
120 = N
So it takes 120 people to dig the same hole in 5 minutes
To see the logic of this, we need to dig the hole 60 times as fast......therefore....we need 60 times as many people.... and 60 x 2 = 120.....!!!
I always find these questions super tricky.
I am going to do it without algebra. :)
2 people take 5hours
If you have more people, it would take less time - that makes sense doesn't it?
so
2*5people take 5 ÷ 5 hours
10 people take 1 hour
now 5 minutes is 5/60=1/12 of an hour
10*12 people would take 1/12 hours
120 people will take 5 minutes
Of course they would all get in each others way so I do not think it would really work that way. LOL