Starting with a sample of pure , 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is
- (A)10 minutes
- (B)15 minutes
- (C)5 minutes✓ Correct
- (D) minutes
Answer: (C)
Solution
If has decayed, then remains, and means three half-lives have elapsed. Since these three half-lives occupy minutes, one half-life is minutes.
JEE Main · 2005 · 08 May 2005 · Offline · Single correct option