Here is your answer
Money saved on each successive day is-
$3, &5, $7....
Clearly it forms an AP,
where
a1= 3
common difference, d= 2
n=20
So,
using formula
Tn= a1+(n-1)d
T20= 3+(20-1)2
= 3+ 19×2
= 3+ 38
=41
So, money saved on August 20= $41
Sum of money saved upto August 20 =
n/2 (a1+T20)
= 20/2 (3+41)
= 10× 44
= $440
HOPE IT IS USEFUL
Let's forget for the tie being the cost ($3.5)of the 1st fifth of a mile:
Taxi charge excluding $3.5, is $13.95 - $3.5 = $10.45.
If each of the 5th (1/5) of a mile costs $0.55, then with $10.45 we can drive:
10.45/0.55 = 19 fifth of a mile. Add to that the 1st fifth = 20 fifth of a mile
20 fifth = 20 x 1/5 = 4 miles (answer)
Step-by-step explanation:



b.





c.






Answer:
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Step-by-step explanation:
Given

Required
The standard deviation
First, calculate the expected value E(x)

So, we have:


Next, calculate E(x^2)

So, we have:


The standard deviation is:




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