MATHEMATICS

What single discount is equivalent to two successive discounts of $20\%$ and $15\%$?

What would be the compound interest of $\mathrm{Rs}.25000$ for $2$ years. at $5\%$ per annum?

The ratio of the quantities of an acid and water in a mixture is $1 : 3$. If $5$ litres of acid is further added to the mixture,the new ratio becomes $1 : 2$. The quantity of new mixture in litres is?

The value of $3÷\left[\left(8-5\right)+\left\{\left(4-2\right)+\left(2+\frac{8}{13}\right)\right\}\right]$ is:

If $x * y= (x + 3{)}^2 (y - 1)$, then the value of  $5 * 4$ is_____.

If $x * y= (x + 3{)}^2 (y - 1)$, then the value of  $5 * 4$ is_____.

If the selling price of $10$ articles is equal to the cost price of $11$ articles, then the gain percent is_____.

If ${17}^{200}$ is divided by$18$, the remainder is_____.