Expressions with variables

Cadets are marching in a parade. There are $5$ cadets in each row. What is the rule for the number of cadets, for a given number of rows? Use '$n$' for the number of rows.

Sita has $3$ more notebooks than Geetha. Find the number of books that Sita has. Use any letter for the number of books that Geetha has.

Peter has '$p$' number of balls. The number of balls with David is $3$ times the balls with Peter. Write this as an expression.

Write an expression for the statement "$y$ is multiplied by $10$ and then $x$ is added to the product.

Write an expression for the statement "$16$ is subtracted from two times $y$".

Write an expression for the statement "$9$ times $n$ is added to $10$"

Write an expression for the statement "$5$ is added to three times $z$"

Parvati has $5$ more books than Sofia. How many books are with Parvati? Write an expression choosing any variable for number of books.

Srinu has number of pencils. Rahim has $4$ times the pencils as of Srinu. How many pencils does Rahim has? Write an expression.

The cost of one fan is $₹ 1500$. Then if the cost of $n$ fans is $₹\_\_\_\_\_$?