AP ICET 10 Sep 2020 Shift 2 Paper

Note The 26 letters of English are given ranks 1.2__26.in the alphabetical order. Then for $1 \leq r \leq 26, r^{\text{th}}$ letter is coded as $k^{\text{th}}$ letter where $7r + 3 = 26M + k \text{ where } 0 \leq k \leq 25$ and M E Z. When k = 0, $k^{\text{th}}$ letter is coded as ‘z’. For example the letter 'E ' is coded as *L’ because when r = 5 and 7r + 3 = 38, then k =12 and $12^{\text{th}}$ letter is 'L'. For decoding the reverse process is used. Based on this answer the questions