Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 40)
40.
(12345679 x 72) = ?
Answer: Option
Explanation:
| 12345679 x 72 | = 12345679 x (70 +2) |
| = 12345679 x 70 + 12345679 x 2 | |
| = 864197530 + 24691358 | |
| = 888888888 |
Discussion:
19 comments Page 1 of 2.
Kumar said:
7 years ago
12345679 * 72.
= 12345679*(9*8).
= 12345679*(10-1)*8.
= (123456790-12345679)*8.
= 11111111*8.
= 88888888.
= 12345679*(9*8).
= 12345679*(10-1)*8.
= (123456790-12345679)*8.
= 11111111*8.
= 88888888.
(9)
Ronit Singh said:
6 years ago
Why the hell you are applying these lengthy methods, just multiply last three digit i.e. 672 with 72 and you will see 8888 as the last 4 digit in the result and in option only A & B options are with 8888. So option B is the answer as when we multiply a 8 digit long number with two digit number then answer can not be in 8 digit long number. So answer is option B.
(4)
Jaga said:
4 years ago
@Krishna.
Given number is 12345679 not 123456789.
Given number is 12345679 not 123456789.
(3)
Swapnil Dalvi SD said:
6 years ago
Thanks @Kumar.
(1)
Daring Deep said:
9 years ago
One shortcut method is to check the divisibility of numbers by 9 since 72 is divisible by it.
In options, every no except answer is not divisible by 9.
In options, every no except answer is not divisible by 9.
(1)
Kiran said:
9 years ago
Yes, Checking with divisibility rules is easy.
(1)
Sindhiya Mary KV said:
3 months ago
Thanks for giving explanations.
Charan said:
1 decade ago
The best method is:
12345679*9=111 111 111
12345679*(72)=12345679*(9*8)=888 888 888
I hope this will help
12345679*9=111 111 111
12345679*(72)=12345679*(9*8)=888 888 888
I hope this will help
Jaga said:
4 years ago
@Krishna.
Given number is 12345679 not 123456789.
Given number is 12345679 not 123456789.
Krishna said:
4 years ago
@Kumar
123456789 * 9 = 1111111101, then how do you get 111111111? Explain.
123456789 * 9 = 1111111101, then how do you get 111111111? Explain.
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