54 I believe if this is what I think it is the end of the world as we see it the most hardest math riddle to have ever existed 61-47 = 14
47+7=54 54+7= 61 therefore the world as we know shall come to a end at 2:08 PM Central time
Answer:
121.5
Step-by-step explanation:
Find the mean of the last 4 numbers.
Dup= 72 miles
<span>ddown= 120 miles </span>
<span>v= riverspeed </span>
<span>rup= 32mph - v </span>
<span>rdown= 32mph + v </span>
<span>t both ways= t </span>
<span>d=r*t </span>
<span>d/r=t </span>
<span>t=ddown/rdown </span>
<span>t=dup/rup </span>
<span>dup/rup = ddown/rdown </span>
<span>(72)/(32-v)=(120)/(32+v) </span>
<span>3840-120v=2304+72v </span>
<span>1536=192v </span>
<span>v=8</span>
Answer:
-19.9 ft.
Step-by-step explanation: