SOLUTION: Walking lights are placed around the perimeter of a rectangular garden 30 feet by 16 feet. and are placed 18 inches apart. How many lights are needed?

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Question 1187239: Walking lights are placed around the perimeter of a rectangular garden 30 feet by 16 feet. and are placed 18 inches apart. How many lights are needed?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website!
This is a very unrefined way to think of it.
18 inches is 1.5 feet.
One can put 21 lights from corner to corner on each of the 30 foot lengths.

9 lights along each of the 16 feet lengths not including the corners.

Only estimating 60 lights.

Answer by ikleyn(52787)   (Show Source):
You can put this solution on YOUR website!
.

Speaking formally, it is unclear, what is the meaning of these words " 18 inches apart " in this problem.

How we should understand these words for walking lights located near the corner points ?
Should we (and/or can we) cut the angles there ?

Usually, these words " 18 inches apart " mean 18 inches along the sides.

The standard and traditional way to solve such problems is to calculate the perimeter and to divide it by the elementary distance.

Then the quotient gives you the answer.

But in this problem the perimeter is   2*(30+16) = 2*46 = 92 ft   and it is not divisible by 18 inches (= 1.5 ft) without the remainder,

so the answer is " It is not possible formally satisfy the problem's requirements ".

So, I would say that the person who composed this problem, did not take care to make this problem SELF-CONSISTED.