RRB NTPC Mains or Stage 2 Model Paper 3 with solutions

Concept:This is a coded-addition pattern based on the sum of digit differences of the two numbers.Explanation:For $54 + 43$:Digit difference in $54$ is $5-4=1$.Digit difference in $43$ is $4-3=1$.So, result $=1+1=2$.For $60 + 51$:Digit difference in $60$ is $6-0=6$.Digit difference in $51$ is $5-1=4$.So, result $=6+4=10$.For $62 + 72$:Digit difference in $62$ is $6-2=4$.Digit difference in $72$ is $7-2=5$.So, result $=4+5=9$.Answer:The required value is $9$, which is Option D.