Question #df5d8

2 Answers
Oct 7, 2017

31 trees

Explanation:

We know its less than 50 so our starting numbers are:

1,2,3,4...50

It’s not divisible by 2, so cross out even numbers:

1,3,5,...49

It’s not divisible by 3 and the remainder has to be exactly 1 when divided by 3, so that leaves:

1, 7, 13, 19, 25, 31, 37, 43, 49

It’s not divisible by 5 and the remainder has to be exactly 1 when divided by 5, so that leaves:

1 and 31

Since the trees form two lines before there is one left over we know it can’t be 1. Thus there are 31 trees.

Oct 7, 2017

As per given condition of the problem the number of trees (say N ) is such that if 1 is subtracted from N then N-1 is divisible by 2,3 and 5. The least number divisible by 2,3 and 5 is the LCM of 2,3 and 5 i.e 30.

So N-1=30=>N=31 and it is less than 50, So number of trees will be 31.