Ravina is good at stitiching clothes. She stitched some clothes for an exhibition she had planned Some of these clothes were donated by her to orphan children in her locality while other clothes were sold in the exhibition. How are the two activites different from each other?

Pavni's mother had just washed all the white clothes. She was telling her friend that the whiteness of white clothes was decreasing with every wash and even new white clothes appeared to be like old ones after a few washings. Pavni, who is a student of class 10, was listening to her mother's complaint. Pavni then went to the market and purchased a particular 'dye'. She asked her mother to dissolve a little of this dye in a bucketful of water and soak the washed white clothes in the solution of dye for some time. Pavni's mother did the same. After sometime, the clothes were taken out of the bucket, rinsed well and spread on clothes line for drying. Pavni's mothers observed that the whiteness of washed white clothes had increased a lot after applying a little of the dye. Pavni's mother did not know why on applying little of a certain dye to washed white clothes, their whiteness had increased manifolds. Pavni explained everything to her mother. (a) What could be the 'dye' applied by Pavni's mother to the washed white clothes by dissolving in water ? (b) What does the application of this dye make the washed white clothes look even more white (or shining white) ? Explain. (c) What values are displayed by Pavni in this episode ?

Tina had 20m 5cm long cloth. She cuts 4m 50 cm length of cloth from this for making a curtain. How much cloth is left with her?