In order to find the answer to the question, there has to be an understanding of what Avogadro's Number is. Avogadro's Number (6.02 × 10²³ particles/mole) represents the number of particles (molecules/atoms) that are in one mole of a substance.
Thus, if 1 mole contains 6.02 × 10²³ particles
Then let x moles contain 5.25 × 10²⁹ particles
⇒ (6.02 × 10²³) x = 5.25 × 10²⁹
⇒ x = (5.25 × 10²⁹) ÷ (6.02 × 10²³)
⇒ x = 8.72 × 10⁵ moles
Thus the number of moles of sucrose in 5.25x10^29 sucrose molecules is
8.72 × 10⁵ moles
