Question

Question #df5d8

Answer 1

`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.

Answer 2

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.