A number consist of two digit whose product is 30. if unit's digit is subtracted from ten's digit, 1 is obtained,find the number.

Asked by  | 30th Nov, 2012, 11:56: PM

Expert Answer:

let unit digit=X
Therfor ten's digit=X+1
now, X*(X+1)=30
or, X^2+X-30=0
or, X^2+6X-5X-30=0
or, X(X+6)-5(X+6)=0
or, (X-5)(X+6)=0
or, X=5 or -6
 
X can not be -6.
ther for X=5
X+1=6
 
Therfor, number=65

Answered by  | 1st Dec, 2012, 12:07: AM

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