Question

A four digit number 4ab5 is divisible by 55. Then determine the value of a− b.

Answer 1

Answer:

If a number is divisible by both 5 and 11 then such number should be divisible by 55

Divisibility of 11

sum of digits at odd places=5+a

sum of digits at even places=4+b

a number is divisible by 11 if the sum of digits at odd =even places

if,a=0 then b=1 [5+0=4+1]

so,a-b=-1

Divisibility of 5

If any no. ends with 0 or 5 then such no. is divisible by 5.

here,4015 is easily divisible by 5 as this number ends with 5

Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation:

Answer:

If a number is divisible by both 5 and 11 then such number should be divisible by 55

Divisibility of 11

sum of digits at odd places=5+a

sum of digits at even places=4+b

a number is divisible by 11 if the sum of digits at odd =even places

if,a=0 then b=1 [5+0=4+1]

so,a-b=-1

Divisibility of 5

If any no. ends with 0 or 5 then such no. is divisible by 5.

here,4015 is easily divisible by 5 as this number ends with 5