Calculate the formula according to the meaning of the question:

5x6=30

So six people a * * * thirty minutes.

Integer multiplication starts from the unit and multiplies the first factor by the number on each bit of the second factor in turn; Multiply by the number on the second factor, and the last digit of the number will be aligned with the second factor; Add up the numbers multiplied by several times.

Multiplication principle:

If the dependent variable f is directly proportional to the independent variables x 1, x2, x3, ..., xn and each independent variable are qualitatively different, it will be meaningless to lack any independent variable f.

In probability theory, an event needs to be divided into n steps, the first step 1 includes M 1 different results, the second step includes M2 different results, and the n step includes Mn different results. Then this event may have n = m 1× m2× m3×…× Mn different results.