What points do we conclude from dimensional analysis ? Explain the principle of homogeneity of dimensions.

(i) How many significant figures are there in the following quantities ?
(a) $10.163,$
(b) $1.67\times {10}^{-17},$
(c) $0.270,$
(d) $1.496,$
(e) $15000,$
(f) $2.4300,$
(g) $0.001040$

(ii) Round off the following numbers to three significant figures.
(a) $3.264,$
(b) $0.9462,$
(c) $1.667,$
(d) $1.285,$
(e) $45.875$