1) 8:12 is the same as 8/12 and that simplified is 2/3 or 2:3
2) 15:42 is 15/42 and that simplified is 5/14 or 5:14
3-6 are the same
7) 340miles per 5hours is how many miles/hour → 340/5 or 68mph
8-10 are the same (but 9 and 10 are prices instead of speed)
11) 8/21 simplified is simply 8/21, and 16/40 simplified is 2/5 so this is false
do the same for #12
13) cross multiply → 15 * 10 = 6x → 150 = 6x → 25 = x
cross multiply for 14-16 as well
17) 3,000,000 ÷ 120 = 25,000 per dollar; 5,000,000 ÷ 175 = 28,571 per dollar the second one is the better buy
18) 16,000:18,000 simplified is 8:9
Number 19 was cut off
20) 15 seconds is 1/4 of a minute so multiply the 12 beats per 15 seconds and the 15 seconds by 4, which yields 48 beats per 60 seconds (per minute)
I hope this helps!!!!