Help will give brainliest

16

Step-by-step explanation:

Step 1: Figure out how many juniors and seniors there are

50(0.6) = 30 seniors

50 - 30 = 20 juniors

Step 2: Find out how many juniors + seniors stay in the program

30(0.8) = 24 seniors in the after-school program

20(0.4) = 8 juniors in the after-school program

Step 3: Find the difference

24 - 8 = 16

And we have your final answer!

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm