Learn
If all of the telephone extensions in a certain company must be even numbers, and if each of the extensions is formed using the digits 1, 2, 3, and 6, what is the greatest number of four-digit extensions that the company can have (repetitions are allowed) ?
156
64
48
256
128
156
64
48
256
128
Solution
Four digit numbers has for spaces.
__ __ __ __
Since, extensions must be even numbers the units digit should be either 2 or 6.
The unit’s digit have 2 options.
Each of the remaining spaces has 4 options each (since repetition is allowed).
Hence, the total number of extensions that can be formed = 4 × 4 × 4 × 2 = 128
Register & Unlock access to Prep for free
Solution
Keynote
In the following passage there are blanks, each of which has been numbered. For each number, choose the word which fits the blank appropriately from the suggestions provided. Find out the appropriate word in each case. There is a considerable amount of research about the factors that make a company innovate. So is it possible to create an environment (1) to innovation ? This is particularly pertinent (2) for India…
|||||
