Question

Atwo-digit number of which ens digit exceeds unit digit by 5. The number itself is 8 times the sum of
is digies. Find the number
​

Answer 1

Answer:

72

Step-by-step explanation:

let the tens digit number be x

unit digit x - 5

the number will be 10x + x - 5

this is equal to 8 times the sum of digits

sum of digits = x + x - 5

therefore

$10x + x - 5 = 8(x + x - 5) \\ 11x - 5 = 16x - 40 \\ 16x - 11x = 40 - 5 \\ 5x = 35 \\ x = \frac{35}{5} = 7 \\ units \: digit \: = x - 5 = 7 - 5 = 2 \\ the \: number \: is \: 10x + (x - 5) \\ = 10 (70) + (7 - 5) \\ = 70 + 2 \\ = 72$