(iv) Amit saves ₹400 in the first month, ₹ 500 in the second month, in the third month
₹ 600 and so on.
How much will be his total savings in 21 months?
Answers
Answered by
14
Answer:
given
a=400
d=100
An=21
ATQ
An=a+(n-1)d
An=400+(21-1)100
An=400+2000
An=2400
his total saving is 2400Rs.
Answered by
128
Answer:
29400 Rs
Step-by-step explanation:
(A.P) = 400 , 500 , 600....
Term 1 = a = 400
d = 500 - 400 = 100
n = 21
so,
tn = a + (n-1) × d
= 400 + ( 21 - 1 ) × 100
= 400 + 20 × 100
= 400 + 2000
tn= 2400
Sn = n / 2 ( term 1 + tn )
= 21 / 2 ( 400 + 2400 )
= 21 / 2 ( 2800)
= 21 × 1400
= 29400
So his total savings will be 29400 rs
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