The ratio of urea and potash in a mixed fertilizer is 7 : 3. Express the quantity of urea present as percentage of the total amount of fertilizer.

Solution (By Examveda Team)

$$\eqalign{ & {\text{Required percentage}} \cr & = \left( {\frac{7}{{7 + 3}} \times 100} \right)\% \cr & = \left( {\frac{7}{{10}} \times 100} \right)\% \cr & = 70\% \cr} $$