Which of the following ratios is not equivalent to 6: 10?

3/5
9/15
48/80
24/45

The answer is 24/45

Let's check out all choices:
a) 6:10 = 3:5
    6 * 5 = 10 * 3
    30 = 30
Therefore, equivalent!

b) 6:10 = 9:15
    6 * 15 = 10 * 9
    90 = 90
Therefore, equivalent!

c) 6:10 = 48:80
    6 * 80 = 10 * 48
    480 = 480
Therefore, equivalent!

d) 6:10 = 24:45
    6 * 45 = 10 * 24
    270 ≠ 240
Therefore, inequivalent!