Question

The average income on Sunday and Monday of an electrician is Rs 1,800. If

his income on Tuesday is also included, the average income will be Rs 2,100. Find his income on Tuesday.

Answer 1

income for Tuesday is Rs 2700

Explanation:

average is calculated as

average =
`(sum)/(count)`

given his average for the 2 days, Sunday and Monday is Rs 1800 , then use this to calculate the sum for the 2 days.

`(sum)/(2)` = 1800 ( multiply both sides by 2 to clear the fraction )

sum = 2 × 1800 = 3600

given the average is Rs 2100 after adding a third day, Tuesday .

let x be his income on Tuesday and add it to the previous sum

`(sum+x)/(3)` = 2100

`(3600+x)/(3)` = 2100 ( multiply both sides by 3 to clear the fraction )

3600 + x = 3 × 2100 = 6300 ( subtract 3600 from both sides )

x = 6300 - 3600 = 2700

his income on Tuesday is Rs 2700

Answer 2

The electrician's income on Tuesday is Rs 2,700

Explanation:

Note:
The median is the middle number of a sorted distribution.

It is the value that divides the distribution into two equal halves, with half of the values being higher than the median and half being lower.

For the Question:

Let's denote the electrician's income on Sunday, Monday, and Tuesday as S, M, and T, respectively.

We are given two pieces of information:

The average income on Sunday and Monday is Rs 1,800:

`\sf ((S + M) )/( 2 )= 1,800`

Multiply both sides by 2.

`\sf (S+M) =2* 1,800`

`\sf (S+M) =3,600 ..........[i]`

If his income on Tuesday is also included, the average income will be Rs 2,100:

`\sf ((S + M + T) )/(3) = 2,100`

Multiply both sides by 3.

`\sf (S+M+T) =3* 2100`

`\sf (S+M+T) =6,300 ..........[i]`

Substitute this value (S+M) into the second equation:

`\sf (3,600 + T) =6,300`

Subtract 3,600 from both sides:

`\sf T = 6,300 - 3,600`

`\sf T = 2,700`

So, the electrician's income on Tuesday is Rs 2,700.