Answer:
average mass of 4 boys=45
or, average mass of 4 boys=sum of weight of 4 boys/4
or,45=total weight/4
therefore, total weight=180kgs
when a new boy joins average mass becomes 40,so,
average mass of 5 boys=40
or,avaerage mass of 5 boys=sum of weights of all 5 boys/5
or,40=(180+x)/5[since the total weight of 4 boys was 180 kgs from the previous calculation and considering 'x' as the weight of the new boy]
or,200=180+x
so,x=200-180
x=20
therefore the mass of the fifth boy is 20kg
Hey sorry I can’t help but use Mathaway or Photomath to help!
Answer: If you are reflecting the triangle(or coordinate points in general) off of the x or y axis on the upper quadrants, then the reflection would be negative for x.
If you are reflecting the triangle(or coordinate points in general) off of the x or y axis on the lower quadrants, then the reflection would be negative for y.
This is because the lower quadrants are usually negative and the upper quadrants are usually positive according to the x axis. The same thing vice verse with y.
These are the rules that I’m guessing your trying to find. Hope this helps!
Um are there any given value that you have to plug in