To train for a triathlon, Mr. Grey swims, bikes, and runs every day. He bikes 10 times the distance that he swims, and he runs 1.5 miles more than half the miles he bikes. If Mr. Grey covers 25.5 miles on each day of training, how many miles does he swim? Bike? Run?

He bikes 15 miles which is 10 times more than he swims. He runs 9 miles which is half of what he bikes 15/2=7.5. Plus the addition 1.5 miles which is 9. He swims .10 of what he bikes which is 15x.10 which is 1.5 . So he swims 1.5 miles.

Bikes = 15 miles
Run= 9 miles
Swim= 1.5 miles

Add all of them and you get 25.5 which the total amount of miles for his training that day.

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table