Which of the following has the lowest value?

Which of the following has the lowest value?

مندرجہ ذیل میں سے کس کی سب سے کم قیمت ہے؟
Explanation

Atto (a) = 10⁻¹⁸

Femto (f) = 10⁻¹⁵

Nano (n) = 10⁻⁹

Peta (P) = 10¹⁵

So, Atto has the smallest (lowest) value.