Question

A three digit number 4a3 is added to another three digit number 984 to give a four digit number 13b7,which is divisible by 11,find the value of 2a+b

Answer 1

4a3+984=13(8+a)7 from here a can be 0 and 1 only. so 8+a=b .
form divisbilty rule of 11
7+3-(b+1)=9-b must be divisible by 11 .
so b=9 satisfy and a=1
2a+b= 11

Answer 2

here's your solution