N = 20, r = 15;
n C r = ( n * ( n - 1) ( n - 2 ) ... ( n - r + 1 )) / r ! =
20 C 15 = (20 * 19 * 18 * 17 ......8 * 7 * 6) / (15 * 14 * 13 ...* 5 * 4 * 3 * 2 * 1) =
= 15,504
Answer:
They can choose 15 questions in 15,504 ways.
Answer:
See explanation below.
Step-by-step explanation:
Note that in △RST and △UVW
- m∠T=180°-m∠R-m∠S;
- m∠W=180°-m∠U-m∠V.
Since ∠R≅∠U and ∠S≅∠V, then ∠T≅∠W.
In ΔRST and ΔUVW:
- ∠S≅∠V (given);
- ∠T≅∠W (proved);
- ST≅VW (given).
ASA theorem that states that if two angles and the included side of one triangle are congruent to the corresponding parts of another triangle, then the triangles are congruent.
By ASA theorem ΔRST≅ΔUVW.
Distribute the 4.
8 + 12c = 56
Subtract 8.
12c = 48
c = 4
Answer:
67 pages in 1 hour
Step-by-step explanation:
A "unit rate" is a rate expressed with "one unit" in the denominator:
(201 pages)/(3 hours) = (201/3) pages/hour = (67 pages)/(1 hour)
Often, the unit of interest is a time unit. Here, it is 1 hour.