A no consists of two digits whose product is 18 When 27 is sub from the no the digits change their place Find?

Answer 1

63

Answer 2

Let x = units digit let y = tens digit The original number is equal to 10y + x The reversal of the digits results in 10x + y (10y + x) - 27 = 10x + y x + y = 7 x = 7 - y 10y + (7 - y) - 27 = 10(7 - y) + y 9y - 20 = - 9y + 70 18y = 90 y = 5 x = 2 The original number is 52 The new (reversed digits) number is 25 Check QED

Answer 3

Let "t" be the tens digit.
Let "u" be the units digit.
The number is 10t + u.

t·u = 18. [The product of the digits is 18.]
(10t + u) - 27 = (10u + t). [27 less than the original reverses its digits.]

t = 18 / u
10(18 / u) + u - 27 = 10u + (18 / u) [Substituting]
180 / u + u - 27 = 10u + 18 / u
180 + u² - 27u = 10u² + 18 [Multiplying by "u" to get rid of the fractions]
0 = 9u² + 27u - 162
0 = u² + 3u - 18 [Dividing by 9]
0 = (u + 6)(u - 3)
u + 6 = 0 or u - 3 = 0
u = -6 or u = 3
Since t and u are digits, u ≠ -6, so u = 3.
t = 18 / u = 18 / 3 = 6.

t = 6 and u = 3
The number, 10t + u = 63.

Answer 4

Let a and b be the unknown values of the digits.
Then a*b = 18
(ab) - 27 = ba (Where (ab) and ba are not multiplied, and a and b are single digits).
Assuming (a) and (b) are integers, the factors of 18 are:
(1)-(1,18)
(2)-(2.9)
(3)-(3,6)
(4)-(6,3)
(5)-(3,6)
(6)-(18,1)

Substitute these values into the equation: (ab) - 27 = ba
Factors (1) and (6) do not qualify because 18 is a two digit number. The remaining factors are substituted into the equation. It will be seen that factor (4) satisfies the equation.

(ab) - 27 = ba
(63) - 27 = 36 Correct.

1st digit is number 6.
2nd digit is number 3.

Answer 5

Let the number be xy (A 2-digit number)
The 2 digits are 10x and y. This is the general form.
For Eg.,If the numberis 47 then it is formed 10(4) and 7.

product = 18 gives 10xy = 18 gives x = (9/5y) --------P (Say)
also given xy - 27 = yx ---------Q (Say)

Now solve these equations to get the answer.
Solving gives x = 6, y = 3.

I hope that you can understand this simply.

Answer 6

63

Answer 7

63

Answer 8

63

Answer 9

63

Answer 10

ok let me solve ur prob step wise
let the digits be x and y
then given x multyplied by y=18
x=18/y
now the digit is,
10x+y (as 10 mutlyplied by 3 +6 gives 36)
it says if 27 is added it wud interchange so
10x+y+27=10y+x
that gives y(power)2+3y-18
that gives y=3,-6
as -6 cant be possible hence y=3
if y=3
then x=18/3=6
hence the required no. is 36....