Question

find the sum of all 3 digit number which when divided by 11 leaves remainder 5​

Answer 1

Step-by-step explanation:

According to the problem,

A.P. is 104, 115, 126, ......, 995

a = 104, d = 11

n be the number of terms

aₙ = 995

∵ aₙ = a + (n - 1)d

⇒995 = 104 + (n - 1)*11

⇒995 - 104 = (n - 1)*11

⇒891/11 = n - 1

⇒81 + 1 = n

⇒n = 82

∴ $S_{n} =\frac{n}{2}[2a+(n - 1)d]$

$S_{82}=\frac{82}{2}[2*104+81*7]=31775$

_______________________

//Hope this will Helped You//

//Please Mark it as Brainliest//

#BAL  #ANSWERWITHQUALITY