A rectangular room is 4.5 m long, 4 m wide and 3 m high. Find the cost of white washing its walls and the roof at ₹ 15 per square metre.

The external dimensions of a closed rectangular box are 82 cm x 47 cm x 60 cm. If it is made of wood of 1 cm thickness, the internal dimensions of the box are :

1. 80 cm x 47 cm x 60 cm

2. 82 cm x 45 cm x 60 cm

3. 82 cm x 47 cm x 58 cm

4. 80 cm x 45 cm x 58 cm

The outer dimensions of a closed small box are 12 cm x 12 cm x 10 cm. If it is made of 1 cm thick walls, its capacity is :

1. 1440 cm³

2. 1000 cm³

3. 640 cm³

4. 800 cm³