Set up a ratio to compare the two proportions.
x= number hours to remove 30 ton
(2/3 ton)/ 1 hour= (30 ton)/(x hours)
cross multiply
(2/3)(x)= (1)(30)
2/3x= 30
divide both sides by 2/3
x= 30 ÷ 2/3
to divide by fraction, multiply by reciprocal of 2/3
x= 30 * 3/2
multiply numerators
x= (30*3)/2
x= 90/2
x= 45 hours
ANSWER: It will take 45 hours to remove 30 tons of dirt.
Hope this helps! :)