Question 1055438

The average daily income for a certain number of days is rs 25. Excluding the income of rs 54 for
a certain day,  the average income becomes Re 1 less. Find the number of days
 for which the average is Rs 25.
<pre>Let number of days be D
Then total income is: 25D
Excluding Rs 54 makes the new income: 25D – 54, and the number of days: D – 1
We then get the following AVERAGE DAILY-INCOME equation: {{{(25D - 54)/(D - 1) = 24}}}
25D – 54 = 24(D – 1) -------- Cross-multiplying
25D – 54 = 24D – 24
25D – 24D = - 24 + 54
{{{highlight_green(matrix(1,7, D, or, number, of, days, "=", 30))}}}