<span>Let m = speed of motorboat
and c = speed of current
.
When going downstream, current speed is added to boat speed -- and, the total speed is "8 miles downstream in 20 minutes"
.
To convert to "miles per hour" we multiply by 60 mins per 1 hour:
(8 miles/20 mins) * (60 mins/1 hour) = 24 mph
.
This gives us our first equation (1):
m+c = 24
.
When going upstream, the boat speed is reduced by the current -- and, the total speed is "8 miles in 30 minutes".
To convert to "miles per hour" we multiply by 60 mins per 1 hour:
(8 miles/30 mins) * (60 mins/1 hour) = 16 mph
.
This gives us our second equation (2):
m-c = 16
m = 16+c
.
Plug the above into equation 1 and solve for c:
m+c = 24
16+c+c = 24
16+2c = 24
2c = 8
c = 4 mph </span>
Answer:
B) 8 miles
Step-by-step explanation:
because she runs 4 miles very hour, it means she'd run double that amount in two hours, which would be 8. Hope this helps!
Answer:
dimension is 5cm * 4 cm
Step-by-step explanation:
As the plane is parallel to the base, the ratio between plane's length and width is equal to the ratio of that of the base. -> similar shape.
Moreover, it also divided the rectangular prism into 2 smaller rectangular prism. hence the plane is identical to the base. Hence, same dimension.
see photo
Answer:
X<8
Step-by-step explanation:
-3 > X-11
= -3 +11 > X
= 8 >X
X<8