A man repays a loan of Rs 3250 by paying Rs.20 in the first month and then increase the payment Rs15 every month. How long will it take him to clear the loan? what is the last instalment
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Let First month he pays = 20
Second month he pays = 20 + 15
Third month he pays = 20 + 2x15
nth month he pays = 20 + (n-1)x15
As he increases his payment by Rs.15 every month.
Now total payment paid by him = (20) + (20 + 15) + (20 + 2x15) + ...+ {20 + (n-1)x15}
= 3250 [Given]
=> 20n + 15 x n x (n-1)/2 = 3250
=> 15n2 + 25n - 6500 = 0
=> 3n2 + 5n - 1300 = 0
After sonving for n we get,
=> n = 120/6 or -130/6 = 20 or -65/3
But n is the number of months which cannot be negative.
Thus n = 20 months
Second month he pays = 20 + 15
Third month he pays = 20 + 2x15
nth month he pays = 20 + (n-1)x15
As he increases his payment by Rs.15 every month.
Now total payment paid by him = (20) + (20 + 15) + (20 + 2x15) + ...+ {20 + (n-1)x15}
= 3250 [Given]
=> 20n + 15 x n x (n-1)/2 = 3250
=> 15n2 + 25n - 6500 = 0
=> 3n2 + 5n - 1300 = 0
After sonving for n we get,
=> n = 120/6 or -130/6 = 20 or -65/3
But n is the number of months which cannot be negative.
Thus n = 20 months
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