What is the sum of all of the four-digit positive integers that can be written with the digits 1, 2, 3 and 4 if each digit must
be used exactly once in each four-digit positive integer?
1 answer:
Answer with explanation:
Number of four digit numbers using four distinct digit
=Unit placed can be filled in four ways * Tens place can be filled in Three ways * Hundreds place can be filled in 2 ways * Thousand Place can be filled in a single way
=4*3*2*1
=24 distinct numbers
Sum of all four , four digits numbers using 1,2,3,4
= (If we keep 4 at unit place +Keeping 3 at unit place +Keeping 2 at unit place+Keeping 1 at unit place)×6+At tens place (2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)+At hundred's place (2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)+At thousand's Place(2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)
=(24+18+12+6)Unit place+(60)Ten's place +(60)Hundred's place+(60)Thousand's Place
=66660
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Answer:
Step-by-step explanation:
Here, we add up two polynomials shown.
The polynomials are:
In order to add up the 2 polynomials shown, we have to see the "like terms" and add them up.
We add up the "" terms and the constant (number) terms. There is one term with "m", so we leave it like that. Let's add up. Shown below:\
This is the sum of the 2 polynomials shown:
Answer:
0.91517
Step-by-step explanation:
Given that SAT scores (out of 1600) are distributed normally with a mean of 1100 and a standard deviation of 200. Suppose a school council awards a certificate of excellence to all students who score at least 1350 on the SAT, and suppose we pick one of the recognized students at random.
Let A - the event passing in SAT with atleast 1500
B - getting award i.e getting atleast 1350
Required probability = P(B/A)
= P(X>1500)/P(X>1350)
X is N (1100, 200)
Corresponding Z score =