Question

A 4-digit number ends in 3. If you put the number 3 in the first position, the number will decrease by 738. Find the original 4-digit number.

Answer 1

4153

Explanation:

Given:

A 4-digit number ends in 3

Let the number be xyz3

Also,

If you put the number 3 in the first position, the number will decrease by 738 i.e.

new number 3xyz is 738 less than xyz3

xyz3-

3xyz=738

Now from above we can see that a number z when subtracted from 13(from rule of lending in subtraction as 8 is greater than 3) results in 8,

13-z=8

z=13-8

z=5

Then z-y=3, we have z=5 but from previous calculation 1 is lend to 3 so now z is reduced to 4 hence 4-y=3

y=4-3

y=1

then y-x=7, we have y=1 so when a number x when subtracted from 11(from rule of lending in subtraction as 7 is greater than 1) results in 7,

11-x=7

x=11-7

x=4

hence we have now values of x,y and z putting the values in original number we get

4153

and new number is 3415 then

Now 4153-3415=738 !