If ₁₀ 7=0.8451 , then the position of the first significant figure of 7⁻²⁰ is

Step-by-step solution

Let x=7⁻²⁰ aligned ₁₀ x &=-20 ₁₀ 7 &=-20(0.8451) &=-16.902 aligned Hence, the first significant figure is 17 .