There are 7 singers competing at a talent show. In how many different orders can the singers appear?
2 answers:
There are 7 singers competing at the talent show. Thus, 7 singers can appear for the first place. Likewise, the remaining 6 singers can appear for the second place. In a similar fashion, 5 singers can appear for the third place. This will continue in this manner till the last place for which only 1 singer can appear. Therefore, the number of different orders in which the singers can appear is given as:
Therefore, out of the given options, second option is correct.
You might be interested in
First of all, we have to observe this triangles separated by the height. These small and big triangles are similar according to the Angle-Angle-Angle principle.
a. We can find all of these length using the cosine of the angle, Pythagoras theorem and the principle of the similarity of triangles.
b. According to the cosine of the angle we can write that, cosθ = 12/a = 5/13 and from here a = 31.2. After finding that using Pythagoras theorem, we can write that . According to the similarity of the triangles, we can write that 31.2/d = 28.8/12 and d = 13. Applying Pythagoras theorem we find that c = 5.
c. We already gave the answer for this question in part b