Question

6. A number consists of two digits whose
sum is 8. If 18 is subtracted from the
number the digits interchange their places,
then what is the number?
(a) 42
(b) 35
(c) 53.
(d) 44​

Answer 1

• Answer:

(c) 53

• Step-by-step explanation:

Hi there !

we have a number ab

a + b = 8

ab - 18 = ba

10a + b - 18 = 10b + a

10a - a + b - 10b = 18

9a - 9b = 18 | + (9a + 9b)

9a + 9a - 9b + 9b = 18 + 9(a + b)

18a = 18 + 9×8

18a = 18 + 72

18a = 90

a = 90 : 18

a = 5

a + b = 8

5 + b = 8

b = 8 - 5

b = 3

ab = 53

Good luck !