Question

In the following sum, "?' stands for which digit?
?+1?+2?+?3+?1=21?
(A) 4
(B) 6
(C) 8
பின்வரும் கணக்கில் '?' எதைக் குறிக்கிற?
?+1?+2?+?3+?1=21?
(A) 4
(B) 6
(C) 8​

Answer 1

x + (10+x) + (20+x) + (10x+3) + (10x+1) = (210+x)

23x + 34 = 210 + x

22x = 176

176/22 = x = 8

And just to check....

8 + 18 + 28 + 83 + 81 = 218 is a true equation.

So . is 8