plz solve this question urgent
Answers
Answer:
Step-by-step explanation:NASA tested two SR-71 aircraft. ... NASA stands for National Aeronautics and Space Administration. NASA was started on October 1, 1958, as a part of the United States government. NASA is in charge of U.S. science and technology that has to do with airplanes or space.
(i)A four digit number is to be formed from the digits 1,2,3,4,5.
□□□□
ThHTO
Now, ones place can be filled in 5 ways.
Since, repetition is not allowed, tens place can be filled by remaining 4 digits.
So, there are 4 ways to fill ten's place.
Since, repetition is not allowed , so hundreds place can be filled by remaining 3 digits .
So, hundred's place can be filled in 3 ways.
Similarly, to fill thousand's place, we have 2 digits remaining.
So,thousand's place can be filled in 2 ways.
So, required number of ways in which four digit numbers can be formed from the given digits is 5×4×3×2=120
(ii) Now, for the number to be even , ones place can be filled by 2 or 4.
So, there are 2 ways to fill one's place.
Since, repetition is not allowed, so tens place can be filled by remaining four digits.
So, tens place can be filled in 4 ways.
Since, repetition is not allowed , so hundreds place can be filled by remaining 3 digits .
So, hundred's place can be filled in 3 ways.
Similarly, to fill thousand's place, we have 2 digits remaining.
So,thousand's place can be filled in 2 ways.
So, required number of ways in which four digit even numbers can be formed from the given digits is 2×4×3×2=48