Determine the hexadecimal value of a mask that can be used to complement the values of the
first and third bits of f1ag and leave all other bits unchanged. determine the bit operation that
should be used with the mask value to produce the desired result.

You forgot to add the possibilities. we don't know the options from which to choose.

Typically you use a cd.

Hypothesis: volumes of both figures are equal.the volume of  figure 1 is: .the volume of figure 2 is: .since , you can conclude that and . so, .volumes of figures are equal only when an angle in the basis is right (then figures will be the same), in another cases volume of figure 1 is less than volume of figure 2.the hypothesis was not correct in all cases.