Arock contains the radioactive isotope k -40 that decays with a half-life of 1.3 billion years and the radioactive isotope rb-87 that decays with a hlif-lifte of 48.6 billion years. the rock is 100 million years old. the rock currently has 1000 times as many rb-87 atoms as there are k-40 atoms. (that is, neb = 1000 x nk.) when the rock first formed it had m times as many rb- 87 atoms as k -40 atoms. (that is, nrb. o - m x nko.) what is the value of m?

Due sun 06/09/2019 11: 59 pm skip navigation questions correct q 1 [1/1] correct q 2 [1/1] correct q 3 [1/1] untried q 4 (0/1) untried q 5 (0/1) untried q 6 (0/1) untried q 7 (0/1) untried q 8 (0/1) untried q 9 (0/1) untried q 10 (0/1) grade: 3/10 print version start of questions two cyclists, 42 miles apart, start riding toward each other at the same time. one cycles 2 times as fast as the other. if they meet 2 hours later, what is the speed (in mi/h) of the faster cyclist?