Tyson o feditse go direla batho disenthwitšhi tsa muffaletta go lebelela metshameko e megolo.  Senthwitšhi se le sengwe se tlhoka nama le kase e e leng bokete jwa pound mme e ka lekana batho ba le 4. Go tlaa bo go na le batho ba le 20 ba ba tlaa bong ba lebelela metshameko.  Pound ya nama e rekisiwa ka $7.00 mme pound ya kase e rekisiwa ka $3.00.  O tlaa dirisa bokae go reka nama le kase go dira disenthwitšhi tse di lekaneng batho ba le 20?

Mel uses a 900-watt air conditioner for 8 hours a day. This means that each hour the AC uses 900 watts of energy. If he reduces the time he uses the air conditioner by 5 hours a day, how many kilowatts of electric energy will he save in 30 days?
Senthwitšhi se le sengwe se lekana batho ba le 4 mme o ne a direla batho ba le 20, ka jalo o ne a tlhoka go dira disenthwitšhi di le 20/4 = <<20/4=5>>5.
Pound e le nngwe ya nama e bitsa $7.00 mme o ne a tlhoka disenthwitšhi di le 5 ka jalo nama e tlaa bitsa 7*5 = $<<7*5=35.00>>35.00.
Pound e le nngwe ya kase e bitsa $3.00 mme o ne a tlhoka disenthwitšhi di le 5, ka jalo kase e tlaa bitsa 3*5 = $<<3*5=15.00>>15.00.
Fa re kopanya tlhotlhwa ya nama le kase, o tlaa bo a dirisitse 35+15 = $<<35+15=50.00>>50.00
#### 50

An air conditioner uses 900 x 8 = <<900*8=7200>>7200 watts for 8 hours a day.
An air conditioner uses 900 x 5 = <<900*5=4500>>4500 watts for 5 hours a day.
So, Mel saves 7200 - 4500 = <<7200-4500=2700>>2700 watts per day.
That is 2700/1000 = <<2700/1000=2.7>>2.7 kilowatts per day since 1 kilowatt is equal to 1000 watts.
Hence, in 30 days he will have 2.7 x 30 = <<2.7*30=81>>81 kilowatts of electric energy saved.
#### 81