Matt gets a `$1,000` commission on a big sale. This commission alone raises his average commission by `$150.` If Matt's new average commission is `$400`, how many sales has Matt made?

Sam earned a $2,000 commission on a big sale, raising his average commission by $100 . If Sam's new average commission is $900 , how many sales has he made?

Tell how finding commission is similar to finding sales tax.

On 4 sales, Matt received commissions of $300, $40, $x, and $140 . Without the $x , his average commission would be $50 lower. What is x?

An agent gets 5% commission on all sales up to Rs.10000 and 4% commission on all sales exceeding this amount. He gives Rs. 31100 from his sales to his company after deducting his commission. Find his total sales.