Amit Kumar Jha is teaching live on Unacademy Plus
ABOUT ME About me My Name is Amit kumar Jha. After doing my B.Tech , I worked with Aditya Birla Group at various locations Since 2001, I am taking Quant classes for GMAT,GRE,SAT,ACT from various platforms as well as as a freelancer.
Permutation and combination Practice Questions
Question 1 From a total of 5 boys and 4 girls, how many 4person committees can be selected if the commitee must have exactly 2 boys and 2 girls?
Answer We have 5 boys and 4 girls and need to select 2 boys and 2 girls to form a committee. Girls Boys A, B, C,D,E F,G,H, 5-2 select 2 boys 402 select 2 girls -10x6
Ouestion2 ofihas employes there ar ftemale employeesand male empoye hw man wascana3peson omnter reatedf the commitee mustincludethe male employee
ANSWER There are seatsonthe comit seats to dealwth W o tht sat must br ild y th mal mplyeT ith2 Wehave 5 iemale emplyend2 ols terhethisis combination problem 5C2
QUESTION3 91-901+89 891 90 89+89 90 +1 912-1
ANSWER 9-90+8918(68) 89 89! (91 *90-90-1)*(89!)-01.00-90-1 89! =(91-1)*90+1=90 *90)+1=90H
QUESTION4 Kmis taking a math class and the teacher gives a multiple chovice test consisting of 8 questions.feach question has 5 answer choices,and Kim answers every question,in how many diferent ways can she complete the test? 4>
ANSWER Kimis required to answer 8 questions,and each questionhas 5 answers choices to select fom his means that there are 5 possible answer outcomes for each question Question 1:5 answer choices Question 2:5 answer choices Question 3:5 answe choices Question4 5 answer choies
ANSWER The question tells us we have 4 pairs of black socks, 3 pairs of grey socks, and Note that the maximum number of socks we can remove without having a matching pairis 3 Once we select our 4th sock, we are guaranteed to have a matching pair.So our answer is A