The reciprocal is just when you flip the number that you're given. the reciprocal of 7/12 is 12/7
12/30 = 18/45, so first you're going to cross multiply and you'll get (30)(18) = (12)(45). Then you can see that 540 = 540 same number so they're proportional...
BTW THIS WAY IS A LOT EASIER.
12/30 = 2/5
18/45 = 2/5
So yes, in summary, they're proportional to each other. Hope this helps, have a BLESSED and wonderful day! :-)
Total distance = 200 miles
Time needed for the first 100 miles
= 100 ÷ 40 = 2.5 hours
Time needed for the second 100 miles
= 100 ÷ 50 = 2 hours
Total time = 2.5 + 2 = 4.5 hours
Average speed = 200 ÷ 4.5 hours = 44.4 miles per hour
Answer: 30 miles
Step-by-step explanation:
45/6 = 7.5 miles per minute
7.5 x 4 = 30 miles per minute