Can you solve the $20 riddle? ft SMBC Comics' Zach Weinersmith

SI Riddle:
I'm trying to think of these, I know there are 7 base SI units, but so far I only have 5
[SPOILERS AHEAD]

meter, second, kilogram;  kelvin;  ampere;  ???;  ??? (candela? Something with light)
after watching solution
NICE I got most of them, but wtf, is mol a base unit?...

Prisoner puzzle
I already know this, I've been asked this riddle by my maths teacher in primary school. Got it correct then!
The last prisoner chooses a color based on parity of colors of hats in front of them, and dies 1/2 the time. The next person compares what they see with what the other person said. If the parity matches, their hat is whatever we assigned 0 to, otherwise it's 1. The prisoner next in line does the same, and so on.

the true-false riddle... I haven't heard this before
Okay, 2 or 3 minutes passed you just have to cause a paradox/ABSURD value, easily achieved by "you return 10$" which cannot be true, then "or you owe me 1000$"