A metre rule is used to measure the length of a piece of string in a certain experiment. It is found to be 20 cm long to the nearest millimeter. How should thisresult be recorded in a table of results? a. 0.2000m b. 0.200m c. 0.20m d. 0.2m​

Will you chech and finish these for me, because i am stumped with them.

You win the lottery and decide to impress your friends by exhibiting a million-dollar cube of gold. at the time, gold is selling for $ 426.60 per troy ounce, and 1.0000 troy ounce equals 31.1035 g. -how tall would your million-dollar cube be? en cm

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?