PLEASE HELP! For a concert 5,000 tickets were sold, and the proceeds were $72,000. Tickets for children 16 and younger were $10, adults were $20, and seniors 60 and older were $15. There were 3 times more children than seniors at the concert. What system of equations represents the number of children, c, adults, a, and seniors, s, that attended the concert?

A: the first answer is the best option

if there is a total of 5000 tickets, and we know there were adults, children, and seniors, then the equation:
c + a + s = 5000 is correct

if we are using c, a, and s as variables for how many children, adults, and seniors were in attendance, then by matching the corresponding price, we should have the equation:
$72000= 10c + 20a + 15s

lastly, if we know the amnt of children in attendance was 3x more than the amnt of seniors, the equation:
3s = c is best because by multiplying the number of seniors in attendance by 3, you will get 3x more children than seniors

hope this helps, and is correct :)!

40 & 50 in the right corner are the complementary angles as when placed in a sum (added together) they make 90°

Maybe the answer is 20mm. all i really did was just multiply, which is obvious.