18. 80 ning 20% ini toping.

Sonning foizini topish uchun sonni foizga ko'paytiramiz va 100 ga bo'lamiz:

\( \text{Foizni topish:} \text{Son} \times \frac{\% \text{ miqdori}}{100} \)

Masalada berilgan:

• Son = 80
• \( \% \) miqdori = 20%

Hisoblaymiz:

\( 80 \times \frac{20}{100} = 80 \times \frac{1}{5} = \frac{80}{5} = 16 \)

Ответ: 16