Bank Math Master১টি পরীক্ষায় এসেছেপ্রশ্ন ১৩The ratio of the ages of A and B at present is 3 ∶ 1. Four years earlier the ratio was 4 ∶ 1. The present age of B is-ক12 yearsখ24 yearsগ18 yearsঘ36 yearsউত্তর দেখুন