Sonya had 20 dollars to spend on 3 gifts. She spent 8 1 4 dollars on gift A and 4 4 5 dollars on gift B. How much money did she
1 answer:
You might be interested in
<u>Hint </u><u>:</u><u>-</u>
- Break the given sequence into two parts .
- Notice the terms at gap of one term beginning from the first term .They are like
. Next term is obtained by multiplying half to the previous term .
- Notice the terms beginning from 2nd term ,
. Next term is obtained by adding 3 to the previous term .
<u>Solution</u><u> </u><u>:</u><u>-</u><u> </u>
We need to find out the sum of 50 terms of the given sequence . After splitting the given sequence ,
.
We can see that this is in <u>Geometric</u><u> </u><u>Progression </u> where 1/2 is the common ratio . Calculating the sum of 25 terms , we have ,
Notice the term will be too small , so we can neglect it and take its approximation as 0 .
Now the second sequence is in Arithmetic Progression , with common difference = 3 .
Substitute ,
Hence sum = 908 + 1 = 909