Answer:
The answer is 21 minutes
Step-by-step explanation:
We use the equation Xf = Xo + vt
1) At 1:00 PM, child one leaves the starting point heading north at a constant velocity of 6 mi/hr or .1 [mi/min] (divide by 60 to convert from [mi/hr] to [mi/min])
2) He walks for 15 minutes before kid 2 starts walking. In 15 minutes he is able to cover 1.5 [mi]
3) Now, child 2 starts walking and we know that when the range reaches 3 miles, they won´t be able to communicate. So the sum of the final position of child 1 and child 2 must be 3[mi]
- Child 1 final position =>

- Child 2 final position =>

4) Sum the equations and equate to 3
5) Substitute the values we already know
6) in 15 + 6 minutes they will be 3miles apart
7) In 21 minutes they will still be able to communicate with one another.
1.20 - .90 = .30
.30 / 5 = .06 (Same as 30 / 5)
The price of a pound of oranges went up by 6 cents per year.
Hey there!
The answer is D. 1/5
An explanation is in the attached image below.
Hope this helps!
Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present