Ke mmotlana go mogolole ka dingwaga di le tharo, mme ke mogolo go monnake ka dingwaga di le pedi. Dingwaga tsa mme di le ngwe go feta tharo tsa mogolole. Fa o tlhakanya dingwaga tsa rona tsotlhe, o bona di le 87. Ke na le dingwaga di le kae? 

There are 90 rooms at the KozyInn Motel. It takes housekeeping 20 minutes to clean each room. How many hours would it take to clean one-half of the rooms?
A re re X ke dingwaga tsa me. Mogolole o na le dingwaga di le X + 3. Monnake o na le dingwaga di le X - 2. 
Mme o na le dingwaga di le (X + 3) * 3 - 1.
Palo ya dingwaga tsa rona tsotlhe ke X + (X+3) + (X-2) + [(X+3)*3 - 1] = 87.
Fa re atisa ka maikarabo mme re kopanya dipalo tse di tshwanang, re bona X*6 + 9 = 87.
Fa re ntsha robongwe mo matlhakoreng oomabedi mme re arole ka 6 mo matlhakoreng oomabedi, re bona X = 13.
#### 13 

90 * 20 = <<90*20=1800>>1800 minutes
1800/2 = <<1800/2=900>>900 minutes
900 minutes = <<900/60=15>>15 hours
It would take 15 hours to clean 45 rooms at the KozyInn Motel.
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