Answer:
Given speed of trolley = 125 meters per minute
![Speed= 125 meters/minute\\\\Speed =\frac{125}{60}meters/second\\\\Speed=2.083m/s](https://tex.z-dn.net/?f=Speed%3D%20125%20meters%2Fminute%5C%5C%5C%5CSpeed%20%3D%5Cfrac%7B125%7D%7B60%7Dmeters%2Fsecond%5C%5C%5C%5CSpeed%3D2.083m%2Fs)
Now we know that
Distance= Speed x time
Thus for the first case since the time of travel is less than 450 seconds thus the distance traveled is less than
Distance < 2.083 x 450 =937.5 meters
hence depending on the given information we cannot come to any conclusion weather the distance travelled is less than 800 m or greater than 800 m.
For the second case
since the time of travel is greater than 400 seconds
Thus the distance traveled is
![Distance>2.083\times 400=833.2meters](https://tex.z-dn.net/?f=Distance%3E2.083%5Ctimes%20400%3D833.2meters)
which is greater than 800 meters.
Step-by-step explanation:
(a)90 by 10%
90+10% of 90=90(1+0.1)=99
(b)60 by 25%
60(1+0.25)=75
(c)80 by 75%
80(1+0.75)=140
(e)110 by 60%
110(1+0.6)=176
(f)480 by 115%
480(1+1.15)=1032
(g)140 by 45%
140(1+0.45)=203
22.8 grams of element will be remaining after 7 minutes
Further explanation:
Given
![Mass\ of\ element=130g\\Percentage\ of\ reduction=22\%](https://tex.z-dn.net/?f=Mass%5C%20of%5C%20element%3D130g%5C%5CPercentage%5C%20of%5C%20reduction%3D22%5C%25)
The element reduces (1-22%) in one minute.
The process will be repeated 7 times for 7 minutes
If we have to calculate the amount of element after 7 minutes
then the total reduction will be: (1-22%)^7
![Remaining\ amount=130*(1-22\%)^7\\=130*(1-0.22)^7\\=130*(0.78)^7\\=130*0.18\\=22.84g\\Rounding\ off\ to\ nearest\ tenth\\=22.8g](https://tex.z-dn.net/?f=Remaining%5C%20amount%3D130%2A%281-22%5C%25%29%5E7%5C%5C%3D130%2A%281-0.22%29%5E7%5C%5C%3D130%2A%280.78%29%5E7%5C%5C%3D130%2A0.18%5C%5C%3D22.84g%5C%5CRounding%5C%20off%5C%20to%5C%20nearest%5C%20tenth%5C%5C%3D22.8g)
22.8 grams of element will be remaining after 7 minutes
Keywords: Decay, Percentage
Learn more about percentage at:
#LearnwithBrainly
Top triangle((6X9)/2)=27square 7x9=63 parallelogram 7X9=69 right triangle ((7X6)/2)=21 so 27+63+63+21=174