I pulled the same trick I did on One way ticket. Block the water lemmings from entering the balloon. To get around the blocker; dig then have another bomb to stop him then bash across; he’ll stop when he comes out onto the slope.

build up and over the top. Use two bombers to get through to the balloon.

Once again, the backroute straight to the balloon is of course open. But that’s no fun for me.
I’m sure there’s numerous ways. Mine is; I brute-forced basically, using a lot of blockers. One lem dies on the first ledge. Let 3-5 lems come out then set RR to 99, and back to 1 for the last 3-5 lems. Block them upside down once to turn around and block the crowd in the area next to the balloon. Let two go first; one will steps down onto the platform in the middle (just above the gravity pad) dig him down, when the other one falls into his tunnel, near the bottom make him bash across. The digger will drown.
Let three go, block the one in the middle in.
 The very last one dig through the steps over the first chasm to take care of the weasels. Block upside down on the top-most ground to have one turn around and build over the upside down gap. He’ll empty the pool. By this time the basher will finish and fall into the pool. Now have the blocked lemming dig facing right; he’ll enter the pool and open the door for the crowd.

Miller


-Miller can't be the stoker (f).
-Jones is the conductor. Because; Dr. Jones lives in NYC. (e)
     -Dr Miller is the neighbor of the conductor:
        -(Dr Jones's earning: ($2,500)  isn't exactly divisible by 3= can't be neighbor.
        -Dr. Babbit lives in Chicago; not -between there and NY.= can't be neighbor
    -If Dr. Miller is the neighbor then he can't live in NY, we already know Babbit lives in Chicago so Jones is the one living in NYC. (c, e)


I usually figure these puzzles out by making a list and drawing lines. It helps me a lot but then when I go to explain my answer; fail. 

There are a number of ways considering the plethora of skills. I dug a hole then made the hero a climber. Build a wall for the weasels. Heading over to the right; at the block above the pool, upside-down build to the block over the weasels. When he turns around & goes to the balloon and comes back this way build up to the block over the pool now right-side-up and he’ll fall onto your steps and climb up to the laser gate to empty the pool.
Or; when he turns around after upside-down building over the pool just mine and build to turn him around without making a wall for other lemmings.
He’ll circumnavigate the cylinder and when he comes to the gravity pad, this time glitch bash through it.* he goes into the pool, opens the door to the balloon. Turns around, get past the
gravity pad again and go left to the where the crowd is being held and free them.

Of course, you can also just build up underneath the balloon from the start, but that way isn’t any fun for this challenge.

*I didn’t mention this glitch above because you don’t have to do this; you can build over the gravity pad and then mine/bash etc. through the steps to get over it or dig under etc. There is a bunch of ways to get around it but glitching is the easiest way.

Dig, and wait for all lemmings to come out. Then make the hero a climber+floater left and after the pool dig another hole (not too far from the pool). Make him come back and free the crowd then when they becomes stuck in the pool build out of it and now they’ll be stuck in the second hole. You should be able to completely avoid the shredder. Now your hero will continue on the left. Mine to the left on the lower platform and build up to the top again, be sure to actually touch the top so he can get back up. Free the crowd and then free the way to the balloon. If they’re all spaced close together, you can flip the bottom switch without any problems.

Because of the surplus of builders, you can build to the end and all the way back. Start digging at the start near the very edge of the tower but leave a sliver of terrain on the right. Set RR 99 and once they’re all out, build then dig farther over to the right to open a hole; let the crowd go into the first ‘hole’ and the worker is now separated.

nothing much to it. Just remember to build back left out of the pools to give a lot of room for the group to walk around and get your hero in back of them so he can bash to make a wall in the area where the pit is so nobody dies. Also watch out for the area where you build up to the left if the lemmings don't fall on the water they can die, as it's high.

The way I accomplished it; Make ‘the lemming’ a climber and build over the first pool. You lose 3. Then dig in the block with the downward arrows that do nothing, you will lose quite a bit more here. This will trap the rest lemmings in a small space which is what you want. Build to stop him. When he comes back facing right let him climb out of the hole and dig down at the edge of this block so you can build to the ledge and make contact with it. When that is done, let him go all the way back to the beginning then mine right to the hole where they are all congregated then bash right to the steps. The idea is to give the group the largest area to walk around and waste time in. When he gets done bashing and the group is freed and far away, go ahead and bash through the next obstacle and build over the next pool. Dig through the next three platforms. Bash through the next on the bottom. The group should be almost caught up to you by now. When he gets done, make him a blocker right near the edge of the next pool. Once the crowd turns around reset him and build over the pool then bash through the last obstacle.

wait till the first or second lemming that comes out (right or left) turns around once and merges with another from the entrance then start your 1 lemming digging down through the first block shortly after/next to the entrance.
When they fall through he turns around and build up to the ceiling. He turns around and have him build again to make a stoppable wall (you only need 2 builders in Revolution). He hits the ceiling again and is now alone. Bash, build up to the top area.
Let him turn around and come back. Dig or bash through the steps to free everybody. Now let them all go up and wait until he (who should be last) turns around and everybody else is going back down the steps. Dig through the thing platform then dig and bash few times (actually once of each is only necessary) to fall safely and build to the balloon. There should be enough time for him to finish until the others get there.