Lillian built a staircase out of blocks. She used 3 blocks to make the first step, 6 blocks to make the second step and 9 blocks to make the third step. If she continues using the same pattern, how many total blocks will she have used after making the fourth step?

Type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar.a city water tank holds 20 gallons of water. a technician empties 25% of the tank. how many more gallons of water must be removed from thetank so that it has 5 of the water that it started with: the technician must removemore gallons of water for the tank to have 5 of the water that it started with.