Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 74)
74.
Which one of the following numbers is completely divisible by 45?
181560
331145
202860
2033555
None of these
Answer: Option
Explanation:

45 = 5 x 9, where 5 and 9 are co-primes.

Unit digit must be 0 or 5 and sum of digits must be divisible by 9.

Among given numbers, such number is 202860.

Discussion:
10 comments Page 1 of 1.

Kiran said:   4 years ago
What about option A.

Its sum is 21 divisible by 3.

And also it is divisible by 5 can anyone explain me clearly?
(2)

Naveen said:   5 years ago
What is meant by co-primes?

Vikash said:   6 years ago
18 is not divisible by 5.

Abhishek verma said:   7 years ago
LCM of 45 =9 * 5 .

Add of all digits.
2+0+2+8+6+0=18.
So the number of 18 is divided by 9.

Md Taibur Rahman said:   7 years ago
@ Pooja.

If you take 3 and 5 it will be (3*5)=15.

But it must be 45. So, 3*5 will not be taken through these two are co-prime too.

Pooja said:   8 years ago
For 45 instead of 5 and 9 why can't we take 5 and 3 as these 2 are also coprime?

Ramesh said:   9 years ago
45 = 3*3*5,

So, 181560 = 21,

331145 = 17,

202860 = 18,

2033555 = 23,

So, only 18 can divisible 3 two times hence 202860 is answer.

Ranji said:   9 years ago
Give shortcut method please.

Lakshmipriya said:   10 years ago
I can't understand could please explain clearly.

Sallu said:   1 decade ago
202860
2+0+2+8+6+0=18

18 is divisible by 9
And it is divisible by 5
So that it can divisible by 45(9*5).
(1)

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