Question

If the four digit number 31a4 is a multiple of 9, where a' is a digit,

find the value of a​

Answer 1

$\huge{\green{\underline{\underline{\mathfrak{Solution:}}}}}$

Given,

Four digit number = 31a4

◕➜ 31a4 is a Multiple of 9.

$\red{\underline{\sf{Divisibility\;Rule\:of\;9:-}}}$ ɪꜰ ᴀ ɴᴜᴍʙᴇʀ ɪꜱ ᴇxᴀᴄᴛʟʏ ᴅɪᴠɪꜱɪʙʟᴇ ʙʏ 9, ᴛʜᴇ ꜱᴜᴍ ᴏꜰ ᴛʜᴇ ᴅɪɢɪᴛꜱ ᴍᴜꜱᴛ ʙᴇ ᴅɪᴠɪꜱɪʙʟᴇ ʙʏ 9.

So, 3+1+a+4 = 8+a

$→\;{\sf{8+a = 9}}$

$→\;{\sf{a = 9-8}}$

$➝\;{\bf{a = 1}}$

.:. The Value of a = $\Large\fbox\red{1}$

Hope It Helps You ✌️

Answer 2

Answer:

Step-by-step explanation:

 Sum of digits of multiple of 9 = 9

=> 3 + 1  + a + 4 = 9

=> a= 9 - 8

=> a = 1