Manufacturer claims its cleanser works twice as fast as any other. what tests could be performed to support this claim ? explain your reasoning.

get this cleanser and a different one.

get some dirt.

get two clocks

put equal amounts od cleanser on the dirt and start both clocks

when one has workred stop its clock. same for other.

compare times

i already answered it by 34/s

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.