Step-by-step answer:
Answer to problems of this kind is the reciprocal of the harmonic mean of the time required.
We need to find the average of the speeds, not the average of the time.
The respective speeds are 1/3 and 1/4.
The average of the speeds is therefore (1/3+1/4)/2 = 7/24 (harmonic mean of the time taken).
The time required is therefore the reciprocal of the unit speed,
T = 1/(7/24) = 24/7 = 3 3/7 minutes, or approximately 3.43 minutes.
For this case what you should know is that by definition the volume of the cone is given by:
V = ((pi) * (r ^ 2) * (h)) / (3)
Remembering that:
r = d / 2
Substituting the values:
V = ((pi) * ((d / 2) ^ 2) * (h)) / (3)
V = ((pi) * (((10) / 2) ^ 2) * (12)) / (3)
V = 314.16 ft ^ 3
Answer:
V = 314.16 ft ^ 3
The nearest option is:
300 cu. ft
419.10 because there is a 1 in the tenth place unlike the other number.
<span>2 and 3/4 punds of roast beef 2 3/4 = (4x2) + 3 /4= 11/4 roast beef
</span><span>1 and 7/8 pounds of turkey 1 7/8 = 15/8 </span>turkey
2 1/16 pounds of salami 2 1/16 33/16 <span>salami
</span><span>if you put 1/4 of pound of meat
</span>then 11/4 roast beef divided by 1/4 = 11/4 x4 = 11 sandwiches roast beef
15/8 turkey<span> divided 1/4 = 15/8 x 4 = 15/2 = 7 sandwishes
</span>
33/16 salami divided <span> 1/4 = 33/16 x 4 = 33/ 4 = 8 sandwiches</span>
Answer: A, B, C, and E
Step-by-step explanation:
If both sides are real numbers, then the product will be a real number.
If in at least one of the sides we have a complex number, then the product will be real if:
The other number is zero.
The other number is the conjugate of the first.
This is when:
Suppose we have a number:
z = a + b*i
The conjugate will be:
w = a - b*i
And the product between them is:
(a + b*i)*(a - b*i) = a^2 + a*b*i - a*b*i + b^2 = a^2 + b^2
Then the options that will have a real answer are:
A. (4+5i)(4-5i) = 4^2 + 5^2 = 16 + 25 = 41
B. (4 + 91)*(41 - 9) = 3040
C. (3 + 2*i)*(3 -2*i) = 3^2 + 2^2 = 9 + 4 = 13
E. (312 + 7i)*(312 - 7i) = 312^2 + 7^2 = 97,393
