Question 1205009
the candle is 16 cm long and 1.5 cm in diameter.


it's volume is equal to pi * r^2 * h.
r is the radius.
h is the height.


radius is equal to half the diameter = 1.5/2 = .75 cm


volume is pi * .75^2 * 16 = 9 * pi


it is melted and made into 4 identical candles, each of which is 9 cm long.


you have a total volume of 9 * pi.
you divide that by 4 to get 4 identical volumes of 9/4 * pi.
each of them is 9 cm high.
the volume of each becomes pi * r^2 * 9 = 9/4 * pi
solve for r^2 to get r^2 = 9/4 * pi / pi / 9
simplify to get r^2 = 1/4 square cm.
solve for r to get r = sqrt(1/4) = 1/2 cm.
the diameter is twice that, so the diameter of each of the 4 candles is 1 cm.


if this is correct, then the volume of all 4 of the candles should be equal to the volume of the original candle.
that volume was 9 * pi.


the total volume of the 4 candles is equal to 4 * pi * .5^2 * 9.
this becomes equal to 9 * pi.
since it's the same volume as the original candle, it is correct and is your solution.


your solution is, as best i can determine, that the diameter of the 4 individual candles is equal to 1 cm each.