£800 is divided between Natasha, Richard & Stephen so that Natasha gets twice as much as Richard, and Richard gets three tim
1 answer:
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Answer:
36
Step-by-step explanation:
Here is the correct and complete question: The units digit of a two-digit number is twice the tens digit. If the digits are reversed, the new number is 9 less than twice the original number. What is the original number?
Lets assume the original number be"10y+x". (x is unit digit and y is 10th digit)
∴ if number is reversed then resulting number be "10x+y".
As given: x= 2y
and
Now, solving the equation to get original number.
Distributing 2 to 10y and x, then opening the parenthesis.
⇒
subtracting by (2x+y) on both side.
⇒
subtituting the value of "x", which is equal to 2y.
∴
⇒
subtracting both side by (16y-9)
⇒
cross multiplying
We get,
y=3
∵x= 2y
∴ x= 6
Therefore, the original number will be 36 as x is the unit number and y as tenth number.
Answer:
option (c) The mean age will stay the same but the variance will decrease
Step-by-step explanation:
Case I: For 3 executives of ages 56, 57 and 58
Number of executives, n = 3
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 1
For Case II: For 4 executives of ages 56, 57, 58 and 57
Number of executives, n = 4
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 0.67
Hence,
Mean will remain the same and the variance will decrease
Hence,
The correct answer is option (c) The mean age will stay the same but the variance will decrease