Travis o ne a na le diapps di le 61 mo letlapeng la gagwe. O tlhagisitse di le 9 tse a neng a sa tlhole a di dirisa mme a ikopela tse dingwe di le 18. Go setse di le kae jaanong mo letlapeng la gagwe? 

Each class in a school has 20 students. There are 3 classes. The school as a whole is 50% boys and 50% girls. The first class has 15 girls. The second class has 12 girls. How many boys are in the third class?
Travis o ne a setse ka di-apps di le 61 - 9 = <<61-9=52>>52 morago ga go tlhagisa tse a neng a sa tlhole a di dirisa.
Morago ga go ikopela tse dingwe jaanong o na le di-apps di le 52 + 18 = <<52+18=70>>70 mo letlapeng la gagwe. 
#### 70 

The school has 60 students because 3 x 20 = <<3*20=60>>60
The school has 30 girls because 60 x .5 = <<60*.5=30>>30
The third class has 3 girls because 30 - 15 - 12 = <<30-15-12=3>>3
The third class has 17 boys because 20 - 3 = <<20-3=17>>17
#### 17