Question

Choose the greatest among the following.

• A. 7983
• B. 7989
• C. 9789
• D. 9798

Answer 1

The correct option is D 9798

The place value chart for the numbers is given below:

$\begin{array}{ccccc}\text{Number}& \text{Number of}& \text{Number of}& \text{Number of}& \text{Number of}\\ & \text{thousands}& \text{hundreds}& \text{tens}& \text{ones}\\ 7983& 7& 9& 8& 3\\ 7989& 7& 9& 8& 9\\ 9789& 9& 7& 8& 9\\ 9798& 9& 7& 9& 8\end{array}$

$\underset{–}{9}789$ and $\underset{–}{9}798$ have 9 thousands each, while $\underset{–}{7}983$ and $\underset{–}{7}989$ have only 7 thousands each. Thus, 9789 and 9798 are both greater than 7983 and 7989.

We now need to compare 9789 and 9798.

$9\underset{–}{7}89$ and $9\underset{–}{7}98$ both have 7 hundreds.

Comparing digits at tens place:
$97\underset{–}{8}9$ has 8 tens and $97\underset{–}{9}8$ has 9 tens.
Thus, 9798 is the greatest of the lot.