Sarah buys books from a dealer for her bookstall.

She buys $20$ comic books, $15$ storybooks and $10$ colouring books. A comic book costs $₹ a$. A storybook costs $₹ 5$ more than a comic book and a colouring book costs $₹ 10$ more than a storybook.

Which of the following expression shows the total cost of the comic books?

Sudhir observed the pattern shown below on a cloth. The pattern consists of $4$ patches.

The pattern is repeated n number of times in a $4$ meter long cloth.

Which of the following expressions shows the number of octagon patches on the cloth?

Sudhir observed the pattern shown below on a cloth. The pattern consists of $4$ patches.

The pattern is repeated n number of times in a $4$ meter long cloth.

Write an expression to represent an expressions which shows the total number of patches on the cloth?

Sudhir observed the pattern shown below on a cloth. The pattern consists of $4$ patches.

The pattern is repeated n number of times in a $4$ meter long cloth.

The cloth is cut into two equal halves. Sudhir observed both cloth parts have an equal number of repeating blocks but the last line is not complete. Which of the following expression shows the number of complete repeating blocks?

If the rule used to create the number pattern shown below is of the form $x^{\mathrm{th}} \mathrm{term}=\frac{{\left(x-1\right)}^{\mathrm{th}} \mathrm{term}}{2}+K$, then find the value of $K$.

$250, 130, 70, 40, 25$

If $\square =5, △=3 \text{and} ○=7,$ then $\square +\square +○+○+○+△=$

The length of a rectangle is $y$ times its breadth $x$. The area of the rectangle is: