Natasha and Richard are marking exam papers. Each set takes Natasha 45 minutes and Richard 1 hour. Express the times Natasha and Richard take as a ratio. Give your answer in its simplest form.

Use the x-intercept method to find all real solutions of the equation.x^3-10x^2+27x-18=0

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

Given that abcd is a rhombus, what is the value of x?