Jinal saves rupees 1600 during the first year rupees 2100 in the second year 2600 in the third year if she continues her saving in this same pattern in how many years will she save rupees 38500??
pls solve step by step
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Answer:
Common difference 500
a = 1600
l = 38500
Number of years = [38500-1600]/500
Number of years = 73.8
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modsirisha
Grade 9
follow
1600,2100,2600,....
this is an arithmetic progression with
a= 1600, d= 500
sum of A.P.= n/2[2a+(n-1)d]
38500= n/2[3200+(n-1)500]
770= n[32+(n-1)5]
770=32n + 5n² - 5n
5n²+27n -770=0
n=10,(-77/5)
years can't be negative so 10 years
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