It's a polynomial of degree 2. Every polynomial of degree 2 is a parabola
To put words into equations:
x+y+z =50
x=4y
4y=5z -> z= 4/5 y
Which means
4y+y+ 4/5 y= 50
29/5 y =50
29y=250
Y=29/250
19) B
20) D
21) A
22) B
23) C
24) C
The answer is
2/5 = 0.4
Because
2/5 2 divide 5 = 0.4
