Mosadi wa me o batla gore re arolelane bili ya dijo ka go lekana, mme o batla gore ke tlale 20% ya tips mo godimo ga bili ya rona ya dijo ya $50. Ke dule ke duela bokae?

Four books are arranged on a shelf. The first book is 31 mm thick while the second book is 50 mm thick. The third book is 5 mm less thick than the second book, and the fourth book is twice as thick as the first book. What is the total thickness of the four books?
Fa e le gore bili yotlhe ke $50, tips ya 20% e tla nna $50*20% = $<<50*20*.01=10>>10
Ka go tshwana, fa bili e le $50, go e aroganya ka bogare (1/2) go tla nna $50 * 1/2 = $<<50*1/2=25>>25 e e duelwang ke motho ka bongwe.
Seo se raya gore ke duetse $25 ya bili + $10 ya tips = $<<25+10=35>>35
#### 35 

The third book is 50 - 5 = <<50-5=45>>45 mm thick.
The fourth book is 31 x 2 = <<31*2=62>>62 mm thick.
The total thickness of the four books is 31 + 50 + 45 + 62 = <<31+50+45+62=188>>188 mm.
#### 188