Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Science Chemistry Radioactivity
Half life period of first order reaction is 20 minutes. How long will it take to 75% completion?
1
60 minutes
2
80 minutes
3
40 minutes
4
More than one of the above
5
None of the above