Which number produces an irrational number when multiplied by 1/5?

all of them. 1/3 is irrational, therefore if you multiply it by any other number that number would then become irrational.

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)

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