Answer:
search it up on goggle lll
Answer is B
How I got is because I had to first figure out what 40 seconds worth of heartbeats are equal to. 80 - 48 is 32 divided by 2 is 16. Next, I added 48 and 16 which got me 64. All I had to do next was to add 80 and 16 because the rate of heartbeats per 10 seconds is 16. 80+16=96 and thats how I figured that the answer is B
The solution is attached in the
image below. I am hoping that this answer has satisfied your query and it will
be able to help you in your endeavor, and if you would like, feel free to ask
another question.
D=rt
r=(boatrate+riverrate)=(x+2)mph
d=528ft=528/5280mi=1/10mi
t=1/3hr
remember to keep the same units
so
1/10=(x+2)(1/3)
times both sides by 3
3/10=x+2
minus 2 or 20/10
-17/10=x
-1.7=x
it would be going -1.7mph (means going backwards)
