Question

the thickness of Jacob cell phone is 3/8 in the thickness of Crosby cell phone is less than that of Jacob's which measurements could be the thickness of Crosby cell phone?

Answer 1

To compare 3/8 and 4/7 we need to express both fractions with the same denominator:

`\begin{gathered} (3)/(8)=(3\cdot7)/(8\cdot7)=(21)/(56) \\ (4)/(7)=(4\cdot8)/(7\cdot8)=(32)/(56) \end{gathered}`

Then:

`\begin{gathered} (21)/(56)<(32)/(56) \\ (3)/(8)<(4)/(7) \end{gathered}`

Therefore, 4/7 inch is not correct

Similarly, we can compare 3/8 and 2/5, as follows:

`\begin{gathered} (3)/(8)=(3\cdot5)/(8\cdot5)=(15)/(40) \\ (2)/(5)=(2\cdot8)/(5\cdot8)=(16)/(40) \\ (15)/(40)<(16)/(40) \\ (3)/(8)<(2)/(5) \end{gathered}`

Therefore, 2/5 inch is not correct

Similarly, we can compare 3/8 and 1/3, as follows:

`\begin{gathered} (3)/(8)=(3\cdot3)/(8\cdot3)=(9)/(24) \\ (1)/(3)=(1\cdot8)/(3\cdot8)=(8)/(24) \\ (8)/(24)<(9)/(24) \\ (1)/(3)<(3)/(8) \end{gathered}`

Therefore, 1/3 inch is correct

Comparing 3/8 and 5/6, we get:

`\begin{gathered} (3)/(8)=(3\cdot6)/(8\cdot6)=(18)/(48) \\ (5)/(6)=(5\cdot8)/(6\cdot8)=(40)/(48) \\ (18)/(48)<(40)/(48) \\ (3)/(8)<(5)/(6) \end{gathered}`

Therefore, 5/6 inch is not correct