30 inches to 24 inches what is the percent of change

Hello people, i have a math question that i need with, me, i will give the correct one brainiest, and for the other correct people, a and 5 stars.

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01

Which system of linear inequalities is represented by the graph? x-3y > 6 and y? 2x + 4 x + 3y > 6 and y? 2x - 4 x - 3y > 6 and y? 2 - 4 x + 3y > 6 and y > 2x + 4 no be 2 -1.1 1 2 3 4 5 submit save and exit next mark this and retum be