I don’t see any multiple choice but d3 -343 is factored as (d-7)(d^2+7d+49)
You want to be finding out what two factors (where one of them is a perfect square) has the produce of 63. It seems like 9 x 7 (9 is the perfect square) works.

The square root of 9 is 3 so we can just have

(which just means 3 times the square root of 7).
Yes no yes yes no
hope it helps
4
One in 1200 are not particularly good odds. On the other hand, winning the lotto is 1 chance in 13,000,000 which if you've ever played the lotto you know that those odds are good enough to insure that if you played for the rest of your life and you are 18 not expect to live to 80 and you have 104 [given 2 draw a week] chances of winning per year, it likely won't happen. One in 1200 is better but still not good, especially with only 1 draw.
3
As a fraction her probability of winning is 1/2000 which is 0.000833333 as a decimal. You can put that in as
1
÷
1200
=
if you are not sure how your calculator works.
2
Sample Space = {1,2,3,4 .... 1198,1199,1200}
The outcome depends on sophies number. Either 1 number can be chosen or all of them can.
1
The sample space is the integers from 1 to 1200 inclusive.