(2x)sqrt 2- 64y2 is the answer
Answer:
The boat traveling at 24 kph when John goes downstream.
Step-by-step explanation:
We are given the following in the question:
John has a boat that will travel at the rate of 15 kph in still water.
Let x be the speed of the current.
Speed of boat in upstream
Speed of water in downstream
Relation:
We have to find the speed of boat in downstream.
Time to travel upstream for 35 km = Time to travel 140 km downstream
Thus, speed of current is 9 kph.
Speed of boat in downstream = 15 + 9 = 24 kph.
Thus, the boat traveling at 24 kph when John goes downstream.
Answer:
Kenny is 18 years old Andrew is 10 years old Tim is 30 years old and Cameron is 5 years old
Step-by-step explanation:
Let a be Kenny's age , b be Andrew's age , c be Tim's age , d be Cameron's age
( b < a , b<c , d<b)
Kenny is 8 years older than Andrewn = > a = b + 8 (1)
Tim is 3 times as old as Andrew => c = 3 . b (2)
Cameron is 5 years younger than Andrew => d = b-5 (3)
The combined age of the four is 63 => a+b+c+d = 63 (4)
(1),(2),(3),(4) => b+8 + b + 3b + b-5 = 63 <=> 6b + 3 = 63 <=> b = 10
=> a= 10+8 =18, c = 3 . 10 = 30, d= 5
Solving a system of equations we can see that:
They need to use 80kg of the 60% chocolate and 20kg of the 40% chocolate.
<h3>
How to find how much of each candy needs to be used?</h3>
Let's define the variables:
- x = kilograms of the 40% chocolate.
- y = kilograms of the 60% chocolate.
They want to make 100kg, then:
x + y = 100
And the concentration must be of the 56%, then we can write:
x*0.4 + y*0.6 = (100)*0.56 = 56
Then we have a system of equations:
x + y = 100
x*0.4 + y*0.6 = 56
To solve this, we can isolate x on the first equation to get:
x = 100 - y
Now replace that in the other equation:
(100 - y)*0.4 + y*0.6 = 56
40 + y*0.2 = 56
y*0.2 = 16
y = 16/0.2 = 80
This means that they need to use 80kg of the 60% chocolate and the other 20kg of the 40% chocolate.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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