Hint: Start by looking at the 6 and 4 on the top row.

Answer:

Hint: One of the words is AREA.

Answer: The words are star, tare, area, reap.

Hint: How many baths could be filled in 24 hours?

Answer: 80 minutes.

In 24 hours:

- the cold tap could fill 72 baths
- the hot tap could fill 48 baths
- the plug could drain 90 baths
- the leak could drain 12 baths

Therefore, in 24 hours, we have 72 + 48 - 90 - 12 baths full = 18 baths.

Therefore each bath would take 80 minutes to fill.

Hint: Don't look at the first letters.

Answer: Duck.

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

Hint: Every word must contain the central letter.

Answer:
Common words: aim, alarm, alms, am, amp, arm, imp, impala, lamp, limp, lump, ma, mail, map, mar, maul, mu, mural, palm, plasma, plum, pram, prim, primal, prism, psalm, puma, ram, ramp, rim, rump, salami, slam, slim, slum, slump, sum.

All words: aim, aims, alarm, alarms, alarum, alarums, alma, almas, alms, alum, alums, am, ama, amas, ami, amia, amias, amir, amirs, amis, amp, amps, ampul, ampuls, amu, amus, amusia, arm, arms, arum, arums, asarum, imp, impala, impalas, imps, ism, lam, lama, lamas, lamia, lamias, lamp, lampas, lamps, lams, larum, larums, lima, limas, limp, limpa, limpas, limps, lum, lump, lumps, lums, ma, maar, maars, mail, mails, mair, mairs, malar, malars, map, maps, mar, maria, marl, marls, mars, marsupia, MARSUPIAL, mas, maul, mauls, mi, miaul, miauls, mil, milpa, milpas, mils, mir, mirs, mis, mu, mura, mural, murals, muras, mus, palm, palmar, palms, pam, pams, pima, pimas, plasm, plasma, plum, plums, praam, praams, pram, prams, prim, prima, primal, primas, prims, primula, primulas, primus, prism, psalm, puma, pumas, purism, ram, rami, ramp, ramps, rams, ramus, rim, rims, rump, rumps, rums, salami, salmi, samp, samurai, sim, sima, simar, simp, simular, slam, slim, slum, slump, sum, sump, ulama, ulamas, um, ump, umps.