1. State the problem: We want to find the mass of the wheat bag given that it is 15 kilograms more than the mass of the rice bag, which is 48 kilograms. 2. Define variables: Let $m_r$ be the mass of the rice bag and $m_w$ be the mass of the wheat bag. 3. Write the relationship: The mass of the wheat bag is 15 kilograms more than the rice bag. $$m_w = m_r + 15$$ 4. Substitute the known value of the rice bag mass into the equation: $$m_w = 48 + 15$$ 5. Calculate the mass of the wheat bag: $$m_w = 63$$ Answer: The mass of the wheat bag is 63 kilograms.