What's the total number of different arrangements in dna molecule with 2 base pairs?​

Suppose you use three different scale to weigh a bag of oranges. one scale says the nag weighs 2.1 lb, and third says it weighs 2.1 lb. the actual weight of the bag of oranges is 2.153 lb. which of the following best decribes these results?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?

If t=tall and t=short what will be the physical appearance of the offspring the cross below? a.some will be tall and some will be short b.they will all be tall c.they will all be short d.they will be medium height