Bank Math Master১টি পরীক্ষায় এসেছেপ্রশ্ন ১৪The average age of three boys is 20 years. If their ages are in ratio 3 : 5 : 7, the age of the eldest boy is-কক) 12 yearsখখ) 20 yearsগগ) 28 yearsঘঘ) 32 yearsউত্তর দেখুন