continuity and differentiability of Class 12
Frequently Asked Questions
A man is known to speak the truth 3 out of 4 times
He throws a die and reports that it is a six. The probability that it is actually a six is
A: 3/8
B: 1/8
C: 1/4
D: 1/2
Solution:
Explanation:
Let R,S be the event that the man reports that is a six and the throw is a six respectively.
P(R|S)= the probability that the man reports it is a six when it is a six = probability of speak truth =3/4
P(R|S')= the probability that the man reports it is a six when it is not a six = probability of not speak truth =1/4
P(S)= the probability that throw is six =1/6
P(S')= the probability that throw is not a six =1-1/6=6-1/6=5/6
Now we have to find the probability that the throw is actually six when the man reports it is a six i.e. P(S|R)
By the Bayes theorem,
Final Answer:
Hence the correct option is (A).i.e 3/8
The number of millions in one crore are
A: 10
B: 20
C: 50
D: 100
Solution:
Explanation:
One crore is equal to 100 lakhs.
One million is equal to 10 lakhs.
Therefore,
1 crore = 100/10 million
⇒1 crore = 10 million
Final answer:
Hence, option A is correct.
The number of millions in one crore are 10.
How many days are there in x weeks x days
A: 7x2
B: 8x
C: 14
D: 7
Solution:
Explanation:
One week has 7 days.
Thus, x weeks x days has,
(7×x)+x=7x+x
=8x
Final answer:
Hence, option B is correct.
8x days are there in x weeks x days.
Thirty one crore fifty five lakh thirty
- two thousand eight hundred in numerals is written as
A: 31,55,32,800
B: 3,01,55,32,800
C: 3,15,05,32,800
D: 3,15,53,02,800
Solution:
Explanation:
Thirty one crore fifty-five lakh thirty-two thousand eight hundred can be expressed in the Indian system as,
30,00,00,000+1,00,00,000+50,00,000,+5,00,000+30,000+2,000+800+00+0
=31,55,32,800
Final answer:
Option A is correct, that is
Thirty one crore fifty - five lakh thirty - two thousand eight hundred in numerals is written as 31,55,32,800.
The LCM of two numbers is 495 and their HCF is 5
If the sum of the numbers is 100 then their difference is:
A: 10
B: 46
C: 70
D: 90
Solution:
Explanation:
The LCM of two numbers = 495
The HCF of two numbers = 5
Sum of the numbers = 100
Difference of the numbers = ?
Let one number be x and another number be 100 - x.
Final answer:
The correct answer is option A, that is
The difference between those two numbers is 10.
