In the text are the following conversion factors:
i.1 mi = 1 609 m
ii.1 m = 39.37 in.
iii.1 ft = 30.48 cm
iv.1 in.= 2.54 cm
The 1 on the left hand side is assumed to have the same number of significant figures as the number on the right hand side of each of these equations.However,2 of these conversion factors are exact,and this means they have the equivalent of an unlimited number of significant figures when used in calculations.Which 2 are the exact conversion factors?
A) i and ii
B) i and iii
C) ii and iii
D) iii and iv

Question

Quizplus · Accepted Answer

In conversion factor iii, 1 ft is exactly equal to 30.48 cm, which means it has an unlimited number of significant figures. 
In conversion factor iv, 1 in. is exactly equal to 2.54 cm, which also means it has an unlimited number of significant figures. Therefore, the exact conversion factors are iii and iv.

In the Text Are the Following Conversion Factors