Question:
20 x 3 is a multiple of 3, if the digit x is——–or——— or————.
Solution:
1,4,7
We know that, if a number is a multiple of 3, then the sum of its digits is again a multiple of 3, i.e. 2+0+x+3 is a multiple of 3.
x + 5 = 0, 3, 6, 9, 12, 15 But, x is a digit of the number 20 x 3.
x can take values 0, 1,2, 3,……..9.
=> x + 5 = 6 or 9 or 12
Hence, x = 1 or4 or 7