Given the number to be formed by using the digits 0,2,3,4,6,7
Now assuming counting integers starting from 2
Case-I: if zero on 2nd place
(i) 202_, now here at unit place 5 number can take place except zero {as 2020<2022}, so 5 possible way.
(ii) 20__, now here at ten's place 4 number \left\{3, 4, 6, 7\right\}cantakeplaceandatunitplaceall6numbercantakeplacesototal4 \times 6 = 24possibleway</p><p>Case−II:Ifnon−zeronumberon{2}^{nd}place</p><p>i.e2\mathop{\mathop{_}_{⏟}}_{5}\mathop{\mathop{_}_{⏟}}_{6}\mathop{\mathop{_}_{⏟}}_{6},hereathundredthplace5possibilitywillbethereandatunitandten′splace6 \text{ and } 6possibilitywillbethere,sointotal5 \times 6 \times 6 = 180possiblecases,</p><p>Case−IIIwhencountingintegersstartingfrom3</p><p>\begin{cases}3 & \mathop{\mathop{_}_{⏟}}_{6} & \mathop{\mathop{_}_{⏟}}_{6} & \mathop{\mathop{_}_{⏟}}_{6}\end{cases}heretotal6 \times 6 \times 6 = 216possiblecases</p><p>Case−IVwhencountingintegersstartingfrom4</p><p>(i) If 0, 2 or 3on{2}^{nd}place</p><p>i.e.,\begin{cases}4 & \mathop{\mathop{_}_{⏟}}_{3} & \mathop{\mathop{_}_{⏟}}_{6} & \mathop{\mathop{_}_{⏟}}_{6}\end{cases}heretotal3 \times 6 \times 6 = 108possiblecases</p><p>(ii) If 4on{2}^{nd}place</p><p>i.e.,\begin{cases}3 & 4 & \mathop{\mathop{_}_{⏟}}_{6} & \mathop{\mathop{_}_{⏟}}_{6}\end{cases}heretotal6 \times 6 = 36possiblecases</p><p>So,totalpossiblecaseswillbe5 + 24 + 180 + 216 + 108 + 36 = 569 numbers