15. \(\frac{11}{7}\) qismi 121 ga teng bo'lgan sonni toping.

Sonning \( \frac{m}{n} \) qismi \( a \) ga teng bo'lsa, u holda sonni quyidagicha topish mumkin: \( x = a \div \frac{m}{n} = a \times \frac{n}{m} \).

Masalada berilgan:

• \( \frac{m}{n} = \frac{11}{7} \)
• \( a = 121 \)

Sonni topamiz:

\( x = 121 \div \frac{11}{7} = 121 \times \frac{7}{11} = \frac{121 \times 7}{11} \)

Chunki \( 121 = 11 \times 11 \):

\( x = \frac{11 \times 11 \times 7}{11} = 11 \times 7 = 77 \)

Ответ: 77