 
 <prompt> A school na-akpọ software n'efu virus protection maka 50 njikọ. Nke abụọ software package na-akpọ $40 na-emezie 5 njikọ. Nke abụọ software package na-akpọ $60 na-emezie 10 njikọ. Kedu kwa oke oke, na dollars, gbasara ụlọ ahụ na-akpọ $60 software package mgbe ọ dịghị $40 software package? <response>: Nke a bụ 50/5 = 10 seti nke 5 njikọ na ụlọ, ụlọ ga-achọ ozi nke $40 x 10 = $400 maka ozi nke $40.
Nke a bụ 50/10 = 5 seti nke 10 njikọ na ụlọ, ụlọ ga-achọ ozi nke $60 x 5 = $300 maka ozi nke $60.
N'ime ihe niile, ụlọ nwere ike iji $400 - $100 = $300 site na ịchọ ozi nke $60 mgbe ọ bụla ozi nke $40.

Ọdịkarịa ga-eji 100. 