Answer:
Step-by-step explanation:
14x5
Answer:
C- all numbers less than 13.
Why these are incorrect:
A- If it was "less than or equal to" the sign would have to be "≤"
B- If it was 'greater than or equal to" the sign would have to be "≥"
D- If it was "greater than" the sign would have to be ">"
Answer: 2343 / 256
Explanation
I will do this for you in two forms: 1) adding each term, and 2) using the general formula for the sum of geometric series.
1) Adding the terms:
4
∑ 3 (3/4)^i = 3 (3/4)^0 + 3 (3/4)^1 + 3 (3/4)^2 + 3 (3/4)^3 + 3 (3/4)^4
i=0
= 3 + 9/4 + 27/16 + 81/64 + 243/256 = [256*3 + 27*16 + 64*9 + 4*81 + 243] / 256 =
= 2343 / 256
2) Using the formula:
n-1
∑ A (r^i) = A [1 - r^(n) ] / [ 1 - r]
i=0
Here n - 1 = 4 => n = 5
r = 3/4
A = 3
Therefore the sum is 3 [ 1 - (3/4)^5 ] / [ 1 - (3/4) ] =
= 3 [ 1 - (3^5) / (4^5) ] / [ 1/4 ] = 3 { [ (4^5) - (3^5) ] / (4^5) } / {1/4} =
= (3 * 781) / (4^5) / (1/4) = 3 * 781 / (4^4) = 2343 / 256
So, no doubt, the answer is 2343 / 256
Hi
1 mile = 5280 feet
at 90 mile per hour, you have 5280 *90 = 475 200 feets
an hour is 60*60 = 3600 second
so in 1 second the train travel : 475 200 /3600 = 4752 /36 = 132 feets
so in 10 seconds : 132*10 = 1320 feets.