Answer:
Step-by-step explanation:We can consider the following situation in the form of an Arithmetic Progression.
a = 2.75 , d = 0.25 ( 3 - 2.75 )
AP = 2.75 , 3 , 3.25 , 3.5 ......
(i) Total amount saved in 8 days = Sum of the first 8 terms of the above APN = No.of terms .
[tex]S_{n} = N/2 \ ( 2a + (n-1) d ) \\\\S_{8} = 8/2 \ (2(2.5) + (8-1)0.25)\\ \\S_{8} = 4 \ ( 5 + 7(0.25) )\\\\S_{8} = 4 \ (5 + 1.75)\\\\S_{8} = 4 \ (6.75)\\\\S_{8} = 27[/tex]
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(b)Amount saved on the first day = 2.75
Ten times the amount = 27.5
So,we have to find which term of the AP has the value 27.5.
We have to find N
[tex]a_{n} = a + (n-1)d\\\\27.5 = 2.75 + 0.25(n-1)\\ \\24.75 = 0.25(n-1) \\\\99 = n-1 \\\\n = 100[/tex]
Author:
mikaelaoxbv
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