In$-$class Exercise

One$-$third of the products made by XY Plc$.$ are produced by the soap division. If the soap division makes $21$ products, how many total products are made by XY Plc$.?$

A co spends $\frac{1}{4^{th}}$ of its total revenue on employee payroll expenses. If last week's payroll amounted to $$5,000,$ what was the revenue for the week?

Cameron's salary this year is $$23,400.$ If this is $$1,700$ more than he made last year, what was his salary last year?