Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 40)
40.
(12345679 x 72) = ?
88888888
888888888
898989898
9999999998
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.

Sindhiya Mary KV said:   3 months ago
Thanks for giving explanations.

Jaga said:   4 years ago
@Krishna.

Given number is 12345679 not 123456789.
(3)

Jaga said:   4 years ago
@Krishna.

Given number is 12345679 not 123456789.

Krishna said:   4 years ago
@Kumar

123456789 * 9 = 1111111101, then how do you get 111111111? Explain.

Kamalesh said:   5 years ago
Nice, thanks @Anagha.

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)

Swapnil Dalvi SD said:   6 years ago
Thanks @Kumar.
(1)

Kumar said:   7 years ago
12345679 * 72.

= 12345679*(9*8).
= 12345679*(10-1)*8.
= (123456790-12345679)*8.
= 11111111*8.
= 88888888.
(9)

JAISON said:   8 years ago
12345679 x (70+2).
12345679 x 70 = 864197530,
12345679 x 2 = 24691358,
864197530 + 24691358 = 888888888.

Kiran said:   9 years ago
Yes, Checking with divisibility rules is easy.
(1)


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