11.) The half life of a certain bacteria is 2.45 minutes. At present there were y0 grams of that bacteria, but only 1/128 of this amount remains after some time. How much time has passed.

A. 17 minutes
B. 17.15 minutes
C. 17.6 minutes
D. 20 minutes


12. A given 1600 grams of isotopes has a half life of 32 hours how much time it will decay to have only 25 grams remain?






Do include solution and please huwag lang points habol ty! ​