If n(X)=200,x)=300 and n(XUY)=400
then
Find the value of n(XnY)

Write the fraction or mixed number and the decimal shown by the model

Which situation can be modeled by the inequality 5 + 10w ≥ 45? a. you start with $5 and save $10 a week until you have at least $45. b.you start with 5 baseball cards and purchase 10 cards every week until you have at most 45 cards. c.you start with 5 water bottles and purchases cases of 10 water bottles each until you have a total of 45 water bottles. d.you spend $5 plus $10 per week until you have less than $45.

Asap! i'm not good math and i'm lost.