1. 

Battery X lasts longer than Battery Y.
Battery Y doesn't last as long as Battery Z.
Battery Z lasts longer than Battery X.
If the first two statements are true, the third statement is

A. true
B. false
C. uncertain

Answer: Option C

Explanation:

The first two statements indicate that Battery Y lasts the least amount of time, but it cannot be determined if Battery Z lasts longer than Battery X.