Question

A man saves RS 50 in his month of work .Thereafter he saves Rs 5 more in each succeeding month. how long does it take him to save Rs 725?

Answer 1

Answer:

10 months

Explanation:

First month (a) = 50

2nd month = 55

and so on

Common difference = 5

Let in n months the sum becomes 725

n/2 { 2a + (n-1) d} = 725

n {2* 50 + (n - 1) * 5 }=1450

n(100+ 5n-5) = 1450

5n² + 95 n - 1450 = 0

n²+19n - 290 = 0

(n +29) ( n-10) = 0

so n = 10 but n ≠ -29