verbal arithmetic

difficult / hard, probably impossible

solve (a problem); answer (a question); unravel (a riddle) / comb; untangle (hair)

untie; unravel; undo (a fastening); unwrap / dispel (doubts); clear up (a matter)

mask (cover for the face) / anonymous

to be masked, to wear a mask

Counting, calculation

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

starting afresh

make a fresh start