Please help me if you know this

First you have to subtract 1.3 from 0.75 which equals -0.55. Then you have to add 3/7 to 2 which equals 2 and 3/7. Then you divide 2 and 3/7 by -0.55 which equals 0.9785 and that’s your answer. Sorry I don’t know the answer for the second problem but I hope this helped.

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

Ithink it would be 160 people