To answer this item, we have 4 as the speed of the kayaker in still water and the speed of current be y.
When the karayaker moves upstream or against the current, his speed would be 4 - y. Further, if he moves downstream or with the current, the total speed would be 4 + y. The time utilized for the travel is equal to the ratio of the distance and the speed.
Total time = 9/(4 - y) + 9/(4 + y) = 6
We multiply the equation by (4-y)(4+y)
9(4-y) + 9(4 + y) = 6(4-y)(4+y)
Simplifying,
72 = 96 - 6y²
Transposing all the constants to only one side of the equation and rearranging,
6y² = 96 - 72
y² = 4
y = 2
Hence, the speed of the river's current is 2 miles/hr. <em>The answer is letter B.) 2 miles/hour.</em>
Answer:
x = 2.25 y = 0.75
Step-by-step explanation:
2x = 9.5- 5
2x = 4.5
x = 4.5 ÷ 2
x = 2.25
know we now what is x so in the second one we evaluate x
3(2.25) + 5y = 10.5
6.75 + 5y = 10.5
5y = 10.5- 6.75
5y = 3.75
y = 3.75 ÷ 5
y = 0.75
that's it !
if you want to check your answer you can evaluate x and y so it will be like
2×2.25 + 5
= 4.5 + 5 = 9.5
and
3× 2.25 +5×0.75
= 6.75 + 3.75 = 10.5
Answer: 3.75
Step-by-step explanation:
90*20= total distance between points
1800=
1800/x=50/1
1800=50x
1800/50=x
36=x
it would take 36 hours