 
 <prompt> ```Helmet nke Dan na-akpọ onye ọzọ nke Daniel. Helmet nke Rin na-akpọ onye ọzọ nke Dan na Daniel gara aga. Ọ bụghị na Rin's helmet na-agba 75 craters, onye ọzọ bụrụ Dan's helmet?``` <response>: ```N'ihi na ihe na-eme n'ime snorkel helmet nke Rin na-eme 75 craters, otu Dan na Daniel helmets ha na-akpọ 75-15 = 60 craters.
Ka m gbanwe Dan helmet na-enweghị C craters.
N'ihi na Dan skateboarding helmet na-enweghị craters ọkachamara iri na-enweghị craters ọnụahịa Daniel ski helmet, ihe ọnụahịa nke ọnụahịa ha na-enweghị bụ C + (C-10) = 60
2C = 60 + 10
Ihe ọnụahịa nke ọnụahịa Dan helmet na-enweghị bụ C = 70/2
Dan skateboarding helmet na-enweghị 35 craters.

Nke a bụ 35.``` 