Question

the sum of two digits of numbers consisting two digit is 7.If 27 is added to the number digit are reversed the number is​

Answer 1

Step-by-step explanation:

let the tens unit digit be x and tens digit be y .

x + y = 7 ----------(1)

10y+x +27= 10x +y

x-y = 3------------(2)

adding 1 and 2 , we get

2x = 10

x = 5

y = 2

Answer 2

✫ Number = 25 ✫

Step-by-step explanation:

Given:

• Sum of two digits of a number is 7
• After adding 27 to number its digit are reversed.

To Find:

• What is the number?

Solution: Let the tenth place digit be a and ones place digit be b

• Sum is 7 = (a + b) = 7
• b = 7 – a ........(1)

∴ Number = (10a + b)

• After reversing its digits new number formed will be • (10b + a)

A/q

$\small\implies{\sf }$ 10a + b + 27 = 10b + a

$\small\implies{\sf }$ 10a + (7 – a) + 27 = 10 (7 – a) + a [ From equation 1 ]

$\small\implies{\sf }$ 10a + 7 – a + 27 = 70 – 10a + a

$\small\implies{\sf }$ 9a + 34 = 70 – 9a

$\small\implies{\sf }$ 9a + 9a = 70 – 34

$\small\implies{\sf }$ 18a = 36

$\small\implies{\sf }$ a = 36/18

$\small\implies{\sf }$ a = 2

Hence, the digit at tens place is a = 2 and digit at ones place is (a + b) = 7

→ ( 2 + b) = 7

→ b = 5

And , The number will be (10 x 2 + 5) = 25