Question

if 18x5 is a multiple of 9, where x is a digit, what is the value of x ​

Answer 1

ANSWER -

4

SOLUTION -

18x5 is a multiple of 9

• Sum of its digits is a multiple of 9

➾ 1 + 8 + x + 5 is a multiple of 9

➾ 14 + x is a multiple of 9

Since x is a digit

• x can take values 0 , 1 , 2 , 3 , ... 9

➾ 14 + x can take values 14 + 0 , 14 + 1 , 14 + 2 , 14 + 3 , 14 + 4..., 14 + 9

➾ 14 + x can take values 14 , 15, 16, 17, 18, ... 23

➾ 14 + x = 18

➾ x = 18 - 14

➾ x = 4

Answer 2

Answer:

x = 4 this is your answer