Answer:
1089
Step-by-step explanation:
The original number is A0CD, We have that DC0A = 9 x A0CD.
If A =1, then D = 9 and we have:
9C01 = 9 x 10C9
In order for this expression to be true, the following must also be true:
(C x 9) + 8 must be divisible by 10, which means that C x 9 must end in a 2.
The only multiple of 9 (from 9 to 81) that ends in a 2 is 72.
72 = 9 x 8.
Therefore, C must be 8 and the original number is 1089. Multiply it by 9 to check the answer:
1089 x 9 = 9,081
Therefore, 1089 is correct.
Answer:
68% of the data falls within one standard deviation, 95% percent within two standard deviations, and 99.7% within three standard deviations from the mean.
Step-by-step explanation:
The first one simplified is 2j-2k
30% of 520 is 156
What is the total number of students? you need to divide 260/total number
You can solve this problem by following the steps below:
1. You need the formula for calculate the area of a circle, which is:
A=πr²
"A" is the area of the circle
"r" is the radius of the circle (r=35 centimeters).
2. Now, you must take the derivative. Then, the rate of change of the area is:
dA/dt=(2πr)(dr/dt)
3. The radius of change of the radius "r" with respect to time, is:
dr/dt=6 cm/min
4. Then, you have:
dA/dt=(2πr)(dr/dt)
dA/dt=2π(35 cm)(6 cm/min)
dA/dt=420π cm²/min
