Free points guess my fav color for brainlist

The tiles below are pieces of a normal ecg tracing representing a little less than two heartbeats at a resting rate of 80 bpm. arrange the tiles in their correct order. rank from first to last. do not overlap any tiles.

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?