1. A concert venue is tracking the different types of tickets being sold. For a particular concert, there were three times as many children's tickets sold as adult's tickets, and 120 fewer senior's tickets than adult's tickets. Adult tickets costs $29, while children and senior's tickets get a 20% discount. The concert sold out filling the entire 2500-seat concert venue.

(a) How many tickets were purchased for each different group?

(b) How much money did the concert venue make from ticket sales for the concert?

2. A pharmacy sells cough syrup in 3 different strengths: extra strength contains 12% dextromethorphan, regular containing 8% dextromethorphan, and baby strength containing 4.5% dextromethorphan. The company is out of regular strength cough syrup. How many litres of extra strength cough syrup should be mixed with baby strength cough syrup in order to make 30 litres of regular strength cough syrup?

3. Justine and Richa visited friends in Victoria one weekend. They are coming back on the ferry on Monday morning and need to bike from Tsawwassen to their 11:30am class at SFU 50km away. Richa leaves Tsawwassen at 9am and bikes 20km/h stopping every 10km for 5 minutes. Justine is delayed getting breakfast. She leaves at 10:30am and bikes at a constant speed and without stopping to try and make it to class on time. If Justine catches up with Richa right as she is arriving at her fourth stop, at what time does each friend arrive at SFU? Do Justine or Richa make it to class on time?