Suppose commodity X wil cost 40 paise more than Y after Z years.Then, (4.20 + 0.40Z) - (6.30 + 0.15Z) = 0.40 0.25Z = 0.40 + 2.10 Z= X will cost 40 paise more than Y 10 years after 2001 . i.e in 2011
Converting each of the given fractions into decimal form, we get,5/6 = 0.838/15 = 0.532/3 = 0.663/4 = 0.754/5 = 0.86/7 = 0.85Clearly, 0.85 does not lie between 0.83 and 0.53Hence the required fraction is 6/7.