Question

find the least value of m and n so that the five digit number 56m2n is divisible by 15

Answer 1

Hi there !
Here's the answer:

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Given ,
5-digit No. is 56m2n

¶¶¶ If a No. is to be divisible by 15, then the sum of digits of the number has to be divisible by 3 and the unit's digit of the number is 0 or 5.
(Combining divisibility rules of 3 & 5, as 15 = 3 × 5; where 3 & 5 are the factors of 15)

In the given No., 56m2n

Unit digit = n
n = 0 or 5

Least value that it can take is 0


To find m,
Find Sum of digits
=> 5+6+m+2+0 => 13+m

If m = 5 then sum of digits becomes 18, which is divisible by 3.

•°• Least values of m and n are 5 & 0

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Hope it helps