Speed, S = Distance (d) / Time (t) => S= d/t => t= d/S
Let the speed of boat in still water be x mph
Resulting speed upstream = x-4 mph for a distance of 30 miles
Resulting speed downstream = x-4 mph for a distance of 50 miles
Time taken in both distances is equal.
Therefore,
30/(x-4) = 50/(x+4) => 30(x+4) = 50(x-4) => 30x+120 = 50x-200 => 120+200 = (50-30)x => 20x = 320 => x=320/20 = 16 mph
The speed of boat in still water is 16 mph.
Answer:
is this a question? also, 6/4 is not irrational, it is rational, and an irrational number is a number that cannot be expressed as a ratio of two integers, aka a simple fraction
Answer:
283.5
Step-by-step explanation:
A=πr^2
A=π(9.5^2)
A=π(90.25)
π x 90.25=283.5 (rounded to the nearest tenth)
D. (xy2 + 3z14)(x2y4 – 3xy2z14 + 9z28
Answer:
$31.05
Step-by-step explanation:
8% of 25 is 2
25 + 2 = 27
15% of 27 is 4.05
27 + 4.05 = 31.05
$31.05 is how much she spends