Question

Please answer my first question

Answer 1

Answer:

Step-by-step explanation:

2. option (d)

Solution : let the digits be x and y

so given xy = 18 

           ⇒y = 18/x     ................(i)

so the number is 10x + y 

so now given 

 10x + y - 27 = 10y + x 

⇒9x - 9y = 27

⇒ x - y = 3   ..... (ii)

substituting (i) in (ii)

⇒ x - 18/x = 3

⇒x² - 3x - 18 = 0

⇒ x²  - 6x + 3x - 18 = 0

⇒ x(x - 6) + 3(x - 6) = 0

⇒(x + 3)(x - 6) = 0

so x = - 3, 6

so x cannot be negative

so x = 6

so y = 18/x ⇒ y = 18/6 = 3

so the number is 10x + y 

                         = 10 × 6 + 3

                          = 63       ANSWER

3. option (d)

Solution : Complementary angles are those pair of angles whose sum is 90 degrees.

Let x be the measure larger angle and y be the measure of smaller angle.

According  to the given condition,

x = 2y - 3

We know that x + y = 90,

Substituting we get,

2y - 3 + y = 90

3y = 93

y = 31 degrees

then we get

x = 2 (31) - 3

x = 59 degrees

4. option (b)

HCF of coprimes  is 1