Answer: A) 1260
Step-by-step explanation:
We know that the number of combinations of n things taking r at a time is given by :-

Given : Total multiple-choice questions = 9
Total open-ended problems=6
If an examine must answer 6 of the multiple-choice questions and 4 of the open-ended problems ,
No. of ways to answer 6 multiple-choice questions
= 
No. of ways to answer 4 open-ended problems
= 
Then by using the Fundamental principal of counting the number of ways can the questions and problems be chosen = No. of ways to answer 6 multiple-choice questions x No. of ways to answer 4 open-ended problems
= 
Hence, the correct answer is option A) 1260
Simply present that you would split them up as a factor of two. ( make two lines going either vertically or horizontally. place in varriations, a marble in one line and a marble in the other and then count the leftover
The missing side would be 10
Answer:
The answer is 36.
Step-by-step explanation:
36
/\
6 6
/\ /\
3 2 3 2
Answer:
3 obreros tardaran 225 minutos en completar el trabajo.
Step-by-step explanation:
Sea R la velocidad con la que un obrero puede construir 1 muro.
Sabemos que 15 obreros construyen un muro en 45 minutos, entonces:
(15*R)*45min = 1 muro
Con esta ecuación podemos encontrar el valor R
R = (1 muro)/(15*45min)
Ahora queremos saber cuando tiempo tardan 3 obreros en construir un muro, entonces tenemos que resolver:
(3*R)*T = 1 muro
Reemplazando el valor de R obtenemos:
(3*(1 muro)/(15*45min))*T = 1 muro
T = (1 muro)*(15*45 min)/(3*1 muro)
T = 5*45min = 225 min
3 obreros tardaran 225 minutos en completar el trabajo.