Question

A 3-digit number 4a3 is added to another 3-digit number 984 to give a 4-digit number 13b7 which is divisible by 11. Find the value of (a+b)

Answer 1

13b7 is divisible by 11.

so,(1+b)-(3+7)=? is divisible by 11

(1+b)-10=0 (3+7=10 is less than 11)

1+b=10

b=10-1=9

b=9.

4a3+984=13b7

4a3+984=1397

13(8+a)7=1397

8+a=9

a=9-8=1

a=1.

(a+b)=(1+9)=10

(a+b)=10.