Study the table and answer the following
What is the ratio of the total number of male students to that of female students who opted for Biology in schools A and D together?
| School name | Total number of students enrolled | Percentage of enrolled students who opted for Biology | Ratio of male to female students who opted for Biology |
| A | 900 | 30% | 7:8 |
| B | 400 | 38% | 9:10 |
| C | 1000 | 24% | 5:19 |
| D | 800 | 18% | 5:7 |
The number of sport bicycles sold by a shopkeeper in five years is shown in the following bar graph.
What is the percentage of decrease in the sale of sport bicycles in the year 2021 over that in the previous year?
Using trigonometric formulas, find the value of
\(
\left( \frac{\sin (x - y)}{\sin (x + y)} \right)
\left( \frac{\tan x + \tan y}{\tan x - \tan y} \right)
\)
Simplify the given expression.
\(
\frac{(326 + 222)^2 - (326 - 222)^2}{(326 \times 222)}
\)