C.P. of 21 article = S.P of 18 articles. Let, C.P of 21 articles=x CP of 1 article = x 21 SP of 18 articles=x SP of 1 article = x 18 since x / 21 < x / 18, ⇒ there is a gain ∵ gain = S P − C P = x / 18 − x / 21 = (7 x − 6 x) / 126 = x / 126 gain%= g a i n C P × 100 = (x / 126 ÷ x / 21) × 100 =(x/126×21/x)×100 = 100 / 6 = 50 / 3.

Protective coating: One of the main reasons for applying paint to iron articles is to provide a protective coating that prevents the iron from rusting. Iron tends to rust when exposed to moisture and oxygen, and the paint acts as a barrier that prevents these elements from coming into contact with the iron.

Browse the archive of articles on Nature. The chemical composition of the Galactic halo star J1010+2358 shows extremely low sodium and cobalt abundances, different from most other halo stars.

The Right to Education Act 2009, also known as the RTE Act 2009, was enacted by the Parliament of India on 4 August 2009. It describes modalities of the importance of free and compulsory education for children aged between 6-14 years in India under Article 21 (A) of the Constitution of India.