The ratio of a man's age and his son's age is 7 : 3 and the product of their ages is 756. The ratio of their ages after 10 years will be-

• ক 13 : 8
• খ 13 : 7 ✅ সঠিক উত্তর
• গ 13 : 15
• ঘ 9 : 7