answer the question 4
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RashtraMitra:
siddhart plz answer me
this question
is a bit tough
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Answered by
1
Hello mate the answer is 72. 72-45=27
and 7+2=9, 9x8= 72.
and 7+2=9, 9x8= 72.
bro i need a proper answer.. i need a full method and all dat ...this is just a direct answer
by the way thanks
oh hello siddhartrao
Answered by
1
Let the 1st digit be x and the 2nd digit be y.
Therefore the decimal expansion is xy.
Now,
Given that a number between 10 & 100 is 8 times the sum of its digit.
= > 8(x + y) = 10x + y
= > 8x + 8y = 10x + y
= > 2x = 7y ------------ (1)
Also,
Given that if 45 is subtracted from it, the digits will be reversed.
= > 10x + y - 45 = 10y + x
= > 9x - 45 = 9y
= > x - 5 = y --------------- (2)
Substitute (2) in (1), we get
= > 2x = 7y
= > 2x = 7(x - 5)
= > 2x = 7x - 35
= > x = 7.
Substitute x = 7 in (1), we get
= > 2x = 7y
= > 2(7) = 7y
= > 14 = 7y
= > y = 2.
Therefore the number is 72.
Hope this helps!
Therefore the decimal expansion is xy.
Now,
Given that a number between 10 & 100 is 8 times the sum of its digit.
= > 8(x + y) = 10x + y
= > 8x + 8y = 10x + y
= > 2x = 7y ------------ (1)
Also,
Given that if 45 is subtracted from it, the digits will be reversed.
= > 10x + y - 45 = 10y + x
= > 9x - 45 = 9y
= > x - 5 = y --------------- (2)
Substitute (2) in (1), we get
= > 2x = 7y
= > 2x = 7(x - 5)
= > 2x = 7x - 35
= > x = 7.
Substitute x = 7 in (1), we get
= > 2x = 7y
= > 2(7) = 7y
= > 14 = 7y
= > y = 2.
Therefore the number is 72.
Hope this helps!
:-)
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