Answer:
Option (E) 648
Step-by-step explanation:
the 3 digit number can be represented by the blanks as " _ _ _ "
Now,
we have 10 choices ( i.e 0,1,2,3,4,5,6,7,8,9) available for each place in the blank if no condition is applied.
For the hundreds digit, using the conditions given in the question, we have 8 choices left
as 1 and 0 cannot be included in the hundreds place.
for the tens place
we will have 9 choices left out of 10 ( as 1 choice is less because we cannot have same number as on the hundred place )
similarly, for the ones place we have 9 choices left out of 10 ( as 1 choice is less because we cannot have same number as on the tens place )
Therefore,
Total possibilities = 8 × 9 × 9 = 648
Hence,
Option (E) 648
Answer:
Step-by-step explanation:
48618/9=5402
48618/3=16206
Answer:
Choice D. 15.2%
Step-by-step explanation:
We have a normal...
mean u = 48
standard deviation s = 2
We want P(43 < X < 46)
We standardize.
Consider P(43 < X) = P( (43 - 48)/2 < Z) = P(-2.5 < Z)
P( X < 46) = P( Z < (46 - 48)/2 ) = P(Z < -1)
We want P( -2.5 < Z < -1)
Look at Z-scores.
P( Z < -2.5) = 0.0062
P(Z < -1) = 0.1587
so P(-2.5 < Z < -1) = P(Z < -1) - P(Z < -2.5) = 0.1587 - 0.0062 = 0.1525 = 15.2%
about
Let numbers of books be 'b' and numbers of CDs be 'c'
We can set up two equations:
Equation [1] ⇒

Equation [2] ⇒

We are solving for the number of books and the number of CDs bought
When we have two equations in terms of two different variables;

and

, that we need to solve, then this becomes a simultaneous equation problem.
First, rearrange Equation [1] to make either

or

the subject:


Then we substitute

into Equation [2]






Now we know the value of

which is

, substitute this value into

we have

Answer:
Numbers of books = 13
Numbers of CDs = 7