# Q. In the sum ⊗ + 1 ⊗ + 5 ⊗ + ⊗ ⊗ + ⊗ 1 = 1 ⊗ ⊗ for which digit does the symbol ⊗ stand?

(a) 2

(b) 3

(c) 4

(d) 5

Correct Answer: (b) 3

#### Question from UPSC Prelims 2020 CSAT Paper

**Explanation :**

x+1x+5x+xx+x1=1xx

x + 1x + 5x + xx + x1 = 1xx

=> x + 10+ x + 50 + x +10x + x + 10x + 1 = 100 + 10x + x

=> 24x + 61 = 100 + 11x

=> 13x = 39

=> x = 3