Answer: the speed of the current is 9 mph.
Step-by-step explanation:
Let x represent the speed of the current.
A boat can travel 21 mph in still water. If it travels 270 miles with the current. It means that the total speed with which the boat travelled with the current is (21 + x) mph.
Time = distance/speed
Time spent by the boat in travelling 270 miles is
270/(21 + x)
In the same length of time, it travels 108 miles against the current. It means that the total speed with which the boat travelled against the current is (21 - x) mph.
Time = distance/speed
Time spent by the boat in travelling 108 miles is
108/(21 - x)
Since the time is the same, then
270/(21 + x) = 108/(21 - x)
270(21 - x) = 108(21 + x)
5670 - 270x = 2268 - 108x
108x + 270x = 5670 - 2268
378x = 3402
x = 3402/378
x = 9
Answer:
3
Step-by-step explanation:
Answer:
2nd one: amelia has 7 muffins left after filling 42 boxes
Step-by-step explanation:
Answer:
The answer is 2.5
Step-by-step explanation:
each cube has a volume of 0.125 and the cube can hold 20 of them.
0.125 * 20 = 2.5
Answer:
<u>Given</u>: base = 10.4ft, height = 12.5
Area of octagon = 8(1/2 × b × h)
- 8(1/2 × 10.4 × 12.5)
- 520ft²
Volume of pool = 520ft² × 3ft
Now, 1 cubic ft takes 7.5 gallons to fill.
Therefore, 1560 cubic ft takes,
So, <u>Correct choice</u> - [D] 11,700.