Daily · 2026-09-30
One bite-sized math problem set for the day. Solve the 10 multiple-choice problems and reveal the worked solutions.
The sum of all real solutions of is:
gives or . Sum .
equals:
. So .
For , equals:
.
Which statement is logically equivalent to "if is even, then is even"?
The contrapositive of " even even" is " odd odd". A statement and its contrapositive always have the same truth value.
For and , solve . Then equals:
. So .
The value of is:
.
If and , what is ?
.
The set of units (multiplicatively invertible elements) of is:
The units are the residues coprime to : , four elements.
The number of permutations of in which no element is in its original position is:
.
For the ellipse , the eccentricity equals:
, , . So .