Mark had saved $15 but he then had to pay a bill that cost him $5.76 how much money does he have left

Ineed with number 17 i don’t get it at alll

Which mathematical statements are true? 1) if 3 is an odd number, then 3 times 3 is an even number. 2) if 6 is less than 7, then 4 is greater than 7. 3) six is divisible by 3, and 10 is a multiple of 2. 4) the average of the data is greater than the largest value in the data, or it’s less than the largest value in the data. 5) the slope of a linear graph is its rate of change, and the graph’s y-intercept is the initial value. 6) if an equilateral triangle has equal angles, then all its angles will measure 45°.

Tcan be concluded that % of the seniors would prefer to see more candid pictures in this year's edition of the yearbook.