CUET PG 2022 — Mathematics PYQ

Explanation:
There are two possible cases

Case 1: Five 1's, one 2's, one 3's
$$\text{Number of numbers}=\frac{7!}{5!}=42$$

Case 2: Four 1's, three 2's
$$\text{Number of numbers}=\frac{7!}{4!3!}=35$$

$$\text{Total number of numbers}=42+35=77$$