<u>Answer-</u>
<em>The necklace with 24 shells is longer than the necklace with 18 shells by 9 inches.</em>
<u>Solution-</u>
Length of each dentalia shell = 1.5 inches
Length of the necklace made with 24 shells = 24×1.5 = 36 inches
Length of the necklace made with 18 shells = 18×1.5 = 27 inches
The necklace with 24 shells is longer than the necklace with 18 shells by the amount of ,
= 36 - 27 = 9 inches
∴ The necklace with 24 shells is longer than the necklace with 18 shells by 9 inches.
( ∵ As the numbers are already rounded off or natural numbers, so we don't have to round them off or use the compatible numbers.)