Which comparison is not correct?
0-2<-9
0-8<-4
O-7>-9
08>-9

If 20% of a number is 35, what is 50% of that number?

Hi, can anyone show me how to do this problem? 100 points for this. in advance

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years