Question

You can upgrade lighting at your factory to LED bulbs that cost $6.95 each and last an average of 5 years. It costs $3 in labor to change a bulb. Over a 10-year period, about how much will it cost per year to install LED bulbs in 100 lamps and change the bulbs when they burn out?

Answer 1

Answer: $200.00

Explanation:

$6.95+ $3.00= $19.90

$19.90 * 100= $1,990

$1,990 / $9.95 = $200.00

take the orginal cost 6.95 plus the $3 labor which equals 19.90 then you multiply by the number of bulbs 100 which equals 1990 then divide 1990 by the cost of bulbs 9.95 which equals 200!

Answer 2

Each bulb and the labor to install it costs
.. $6.95 +$3 = $9.95

100 bulbs and 10 years totals (100*10) = 1000 bulb·years. For the price of $9.95, you purchase 5 bulb·years, so the total cost for 1000 bulb·years is
.. (1000 b·y)*($9.95/(5 b·y)) = $1990

Over a 10-year period, installation and replacement of 200 bulbs in 100 lamps will cost $1990. Then the per-year cost is ...
.. $1990/(10 yr) = $199/yr