Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. There is a proposal to increase these seats by 40%, 50% and 75% respectively. What will be the ratio of increased seats?

Explanation:-

Originally, let the number of seats for Mathematics, Physics and Biology be 5x, 7x and 8x respectively.
Number of increased seats are (140% of 5x), (150% of 7x) and (175% of 8x). $$\eqalign{ & = \left( {\frac{{140}}{{100}} \times 5x} \right)\,,\,\left( {\frac{{150}}{{100}} \times 7x} \right)\,{\text{and}}\,\left( {\frac{{175}}{{100}} \times 8x} \right) \cr & = 7x\,,\,\frac{{21x}}{2}\,{\text{and}}\,14x. \cr & \therefore {\text{The}}\,{\text{required}}\,{\text{ratio}}\, = \,7x:\frac{{21x}}{2}:14x \cr & \Rightarrow 14x:21x:28x \cr & \Rightarrow 2:3:4. \cr}$$