On a mission to a newly discovered planet, an astronaut finds gallium abundances of 61.29% for 69ga and 39.71% for 71ga . what is the atomic mass of gallium for this location?
the mass of 69ga is 68.7200amu . the mass of 71ga is 70.9200amu .

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

i'm pretty sure its b i might be wrong though!