Hint: Say what you see.

Answer: A paradox: a pair of Docs.

Or Paramedics: a pair of medics.

Hint:

Answer: Nothing!

Hint:

Answer: Togo: Once upon a time in a land far away, lived a hamster. Every morning, very early, the hamster had to go into the forest and forage for food. Every morning, he would come back hungry and miserable.

Hint: Try working backwards.

Answer: 148.

148 * 6 = 888.

The easiest way is to work backwards and divide successive 8's by 6 until you get an integer:

  8 ÷ 6 = 1.3333
 88 ÷ 6 = 14.666
888 ÷ 6 = 148.

Hint: Every word must contain the central letter.

Answer: Deodorant.

Common words:
   add, adder, adore, adored, adorn, adorned, and, anode, ant, dad, dare, dared, darn, darned, dart, darted, date, dated, dead, dean, dear, den, dent, DEODORANT, do, dodo, doe, don, donate, donated, done, donor, door, dot, dread, drone, droned, end, nod, node, noted, oared, odd, ode, ranted, rated, read, red, road, rod, rode, rodent, rodeo, rooted, tad, tend, toad, toned, tornado, trade, traded, tread, trend, trod, trodden.

All words:
   ad, add, adder, ado, adore, adored, adorn, adorned, and, anode, anted, ardent, atoned, dad, dado, dander, dare, dared, darn, darned, dart, darted, date, dated, dater, dato, de, dead, dean, dear, den, dent, deodar, DEODORANT, derat, do, doat, doated, dodo, doe, doer, don, dona, donate, donated, donator, done, donor, door, dor, dorado, dore, dot, dotard, dote, doted, doter, dread, drone, droned, ed, eddo, end, nard, nerd, nod, nodder, node, noted, oared, od, odd, odder, ode, odea, odeon, odonate, odor, odorant, odored, orad, orated, ordo, oread, rad, radon, rand, ranted, rated, ratooned, read, readd, red, redan, redd, redo, redon, rend, road, roadeo, rod, rode, rodent, rodeo, rondo, rood, rooted, tad, tandoor, tardo, tared, ted, tend, toad, tod, toed, tondo, toned, tornado, trad, trade, traded, tread, trend, trod, trodden, trode.