Subject:
MathAuthor:
lucianoandradeCreated:
1 year agoAnswer:
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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