৯ম - ১৩তম গ্রেড পরীক্ষার প্রস্তুতি
The four walls and ceiling of a room of length 25 ft., breadth 12 ft. and height 10 ft. are to be painted. Painter A can Paint 200 sqr.ft in 5 days, painter B can paint 250 sqr.ft in 2 days. If A & B work together, in how many days do they finish the job?