Answer
Marvette will take 27.5 hours to make 40 necklace.
Work Step by Step
Let's assume the Marvette takes x hours to make 40 necklace..
Now, we will write the proportion for the given details
$\frac{24 necklace}{16.5 hours} = \frac{40 necklace}{x hours}$
so. $ 24\times x= 40\times 16.5$ (Same units cancelled, cross multiplication)
Now divide both sides by 24.
$\frac{24 x}{24} = \frac{660}{24}$
$ x = 27.5 $
Marvette will take 27.5 hours to make 40 necklace.
