Last year you needed about 5 minutes for each Math question on average. This year you only need about 90 seconds for each Math question on average. What is the % change in the time need per question?

Carli has 90 apps on her phone. braylen has half the amount of apps as theiss. if carli has three timesthe amount of apps as theiss,how many apps does braylen have? let b represent the number of braylen's apps and t represent the number of theiss's apps.