RRB Group-D Model Paper 11 with answers for online practice

Given Equation: 21 + 5 × 2 – 21 ÷ 3 = 12

1) + and -

After interchanging signs

LHS = 21 - 5 × 2 + 21 ÷ 3 = 21 – 10 + 7 = 18 ≠ RHS

2) – and ÷

After interchanging signs

LHS = 21 + 5 × 2 ÷ 21 – 3 = 21 + 0.476 – 3 = 18. 476 ≠ RHS

3) – and ×

After interchanging signs

LHS = 21 + 5 - 2 × 21 ÷ 3 = 21 + 5 – 14 = 12 = RHS

4) × and ÷

After interchanging signs

LHS = 21 + 5 ÷ 2 – 21 × 3 = 21 + 2.5 – 63 = - 39.5 ≠ RHS

Hence, “– and ×” is the correct answer.