CUET Preparation Today
If $\phi (n)$ represents Euler quotient function, then what is the value of $\phi (420)$ ? |
92 90 96 98 |
96 |
The correct answer is option (3) : 96 $\phi (420) = \phi (2^3×3×5×7)$ $=\phi (2^2) ×\phi (3) × \phi (5)×\phi (7)$ $= (2^2-2^1) ×(3-1)×(5-1)×(7-1)$ $= 2×2×4×6 = 96 $ |
