HELP PLEASE ASAP !!!!Question 5 of 15
Lead-196 has a half-life of 37 minutes. It decays into thallium-196. Suppose a
sample contains 20 atoms of lead-196 and 60 atoms of thallium-196. About
how old is the sample?
A. 74 minutes
O B. 37 minutes
O c. 111 minutes
O D. 148 minutes