Random Puzzles 

Workings

Hint
Snakes don't have legs.

Answer
6 snakes, along with 7 people and 14 lizards.

Reasoning
We know that for each person (2 legs) there were 2 lizards (4 legs each).

Which means for every person, we can count a total of 10 legs.

Snakes don't have legs, so the total of 70 legs must have been 7 people (and 14 lizards).

This is a total of 21 heads, so the remaining 6 heads were all snakes.

Double-Checking
7 people gives 7 heads and 14 feet.

14 lizards gives 14 heads and 56 feet.

6 snakes gives 6 heads and 0 feet.

For a total of 6 + 7 + 14 = 27 heads, and 0 + 14 + 56 = 70 feet.

Workings

Hint
The most common word begins with the letter V.

Answers
Common: vacuum, vacuumed, vacuuming, vacuums.

Less common: continuum, continuums, muumuu, muumuus.

Much less common: carduus, carduuses, continuua, duumvir, duumviral, duumvirate, duumvirates, duumviri, duumvirs, individuum, individuums, lituus, lituuses, menstruum, menstruums, mutuum, mutuums, paramenstruum, paramenstruums, residuum, residuums, squush, squushed, squushes, squushier, squushiest, squushing, squushy, triduum, triduums, ultravacuum, ultravacuums, weltanschauung, weltanschauungen, weltanschauungs.

Workings

Hint
Don't look at the first letters.

Answer
Duck.

The second letters of each word are the vowels (AEIOU) in alphabetical order, fAwn, bEar, lIon, mOle, dUck.

Workings

Hint
One of the words is FREE.

Answer
Dare, Shin, Typo, Free, and Lawn.