farmer has 10 trees see if you can plant them so there are 5 rows of trees with 4 trees in each row
Yes, this is one of those little teasers where you have to think outside the box. Arrange the trees in a pentagram. There are 5 trees at the vertices, and 5 more where the diagonals intersect. So, draw the lines and you'll see you have 5 intersecting lines, each with 4 trees. Each tree is counted twice.
Am I missing something? five rows of four trees each is 20 trees.
What do you mean?
To determine if the farmer can plant the 10 trees in 5 rows with 4 trees in each row, we can use a simple calculation.
First, we calculate the total number of trees needed for that arrangement by multiplying the number of trees in each row by the number of rows:
Number of trees needed = Number of rows × Number of trees in each row
= 5 rows × 4 trees per row
= 20 trees
If the total number of trees needed is equal to the number of trees the farmer has (10 trees), then it is possible to plant them in 5 rows with 4 trees in each row. Otherwise, it is not possible.
In this case, since the number of trees needed (20 trees) is greater than the number of trees the farmer has (10 trees), it is not possible to plant them in the desired arrangement.