Exercise 3.1

Express the following as a ratio $a:b$ and as a fraction in its simplest (lowest) form.

(i) Rs.750, Rs.1250 (ii) $450\mathrm{c}\mathrm{m}$$450\mathrm{cm}$ , $3\mathrm{m}$$3\mathrm{m}$

(iii) $4\mathrm{k}\mathrm{g}$$4\mathrm{kg}$ , $2\mathrm{k}\mathrm{g}750\mathrm{g}\mathrm{m}$$2\mathrm{kg}750\mathrm{gm}$ (iv) $27\mathrm{m}\mathrm{i}\mathrm{n}$$27\mathrm{min}$ , $30\mathrm{s}\mathrm{e}\mathrm{c}$$30\mathrm{sec}$ , 1 hour

(v) $75^{\circ}$ , $225^{\circ}$

In a class of 60 students, 25 students are girls and remaining students are boys. Compute the ratio of

(i) boys to total students (ii) boys to girls