Multiple choice general knowledge math & puzzles If 60% of a is equal to 120% of b, then 2a - 4b = ? 2a 0.5a 0 3a Reveal answer Fill a bubble to check yourself C Correct answer Explanation If 0.6a = 1.2b, then a = 2b. Substituting a = 2b into the expression 2a - 4b gives 2(2b) - 4b, which is 4b - 4b = 0. Therefore, the result is always zero regardless of the values of a and b.