Answer:
15) 300%
Step-by-step explanation:
15)
Let the item originally cost n dollars.
The new incorrect price is (n-.6n).
So we want to find k such that (n-.6n)+k(n-.6n)=n+.6n
since we actually wanted it to be (n+.6n).
So we have (n-.6n)+k(n-.6n)=n+.6n
Distribute:
n-.6n+kn-.6nk=n+.6n
Subtract n on both sides
-.6n+kn-.6nk=.6n
We are trying to solve for k. So add .6n on both sides:
kn-.6nk=1.2n
Divide both sides by n:
k-.6k=1.2
.4k=1.2
Divide both sides by .4
k=1.2/.4
k=3
So 3=300%.
The incorrect price must be increased by 300% to get to the proper new price.
Here is an example:
Something cost $600.
It was reduce by 60% which means it cost 600-.6(600)=600-360=240
This was the wrong price.
We needed it to be increased by 60% which would have been 600+360=960.
So we need to figure out what to increase I wrong price 240 to to get to our right price of 960.
240+k(240)=960
1+k=960/240
1+k=4
k=3
So 240*300%+240 would give me my 960.
16) Speed=distance/time
In the first half hour, she traveled 5 miles (8:30 to 9).
In 1/3 hour she traveled (5-2)=3 miles (9 to 9:20).
We are told not to do anything where she stayed still.
In the last half hour, she traveled (2-0)=2 miles (9:30 to 10).
The average speed=.
Answer:
5. 200/1 = 200 ft/min
6. 600/3 = 200 ft/min
Step-by-step explanation:
5. The rate of change of a graph is the ratio of vertical change to horizontal change. You are asked to find the rate of change from 1 minute to 2 minutes, so you want to find the distance (ft) at 2 minutes and at 1 minute.
Reading the graph, you see that at 2 minutes, the distance is 400 ft. At 1 minute, it is 200 ft.
So, the ratio of the two differences is ...
change in distance / change in time
__
6. Using the same idea, we want to use the graph values at 4 minutes and 1 minute.
Answer:
x = 4 y = 7
Step-by-step explanation:
x + 3 = -1/2x + 9
x = -1/2x + 6
3/2x = 6
x = 4
y = (4) + 3
y = 7
Answer:
The value of y is 4 cm.
Step-by-step explanation:
First find the lengths of each side (square root of 256 is 16, so each side of the bigger square is 16 cm) of each square (square root of 64 is 8, so each side of the smaller square is 8 cm). Then, since each y value is the same and equal, 16 (length of one side of bigger square) minus 8 (length of one side of smaller square), divided by 2 (because there are 2 y values per length), you get 4 cm. Hope that helps!