One third of a number, z, added to one fifth of the same number is 3/5 . what is the number and why? a) 40/3 , because the equation that represents this sentence is 3z+5z=3/5 . b) 6/5 , because the equation that represents this sentence is 1/3z+1/5=3/5 . c) 3/40 , because the equation that represents this sentence is 3z+5z=3/5 . d) 9/8 , because the equation that represents this sentence is 1/3z+1/5z=3/5 . answer ! : )