Question

A, B, C and D are four 4 digit numbers each having the digit 9 only once in the place shown. None of the other digits are known. What can be said about A, B, C and D?

A.D is the smallest of the four numbers
B.B is larger than C
C.A is the largest of the 4 numbers
D.D is the largest of the four numbers

Answer 1

Hint: Here we will be using the given information and try to use the concept of place value of the digits.

Complete step-by-step answer:
Given: A, B, C and D are four 4 digit numbers each having the digit 9 only once in the place shown. None of the other digits are known. We need to ascertain what can be said about the numbers.
Let us assume that there is a four digit number \[1000x + 100y + 10w + z\], x, y, w and z belongs to the set of Natural numbers and x is the digit of the thousandths place, y is the digit of the hundredths place, w is the digit of the tenths place and z is the digit of the unit place.
Now, in the given numbers only the digit 9 is being known as the given digit, where it is changing its place.
As per the place value of numbers, we can say that 9, when placed in the thousands place is surely going to give a higher value, than anywhere placed.

We see that in case of A, the digit 9 has been placed in the thousandths place, so it is confirmed that among all the numbers provided, is the largest of all the numbers.
Hence, it can be said that option c. is the correct option.

Note: In problems like these, it is to be always remembered that all the information need to be analysed by considering the place value of the numbers