Question

Reggie has enough flour to last for 40 days. If he increases his use of flour by 25%, however, how many days’ worth of flour will he have?

Answer 1

So,

Reggie has enough flour to last for 40 days.

Increasing his use of flour by 25% will reduce how many days of flour he will have by 25%, leaving him with 75% of the original number of days of flour left.  We can do simple multiplication to find our result.
$(0.75)(40) = 30$

If Reggie increases his use of flour by 25%, he will have 30 days' worth of flour.