A four digit number is to be formed using the digits 1 to 7
All digits of the number are different and repetition is not
allowed.
1. How many such numbers can be formed ?
2. How many such numbers are divisible by 4 ?

Answer Posted / sumati

Answer 1:
At unit's place 7 possibilities r dere.
At ten's place 6,
At hundred's place 5,
At thousand's place 4.

Therefore, 7*6*5*4=840

Answer 2:
for any number to b divisible by 4, the last two digit must
b divisible by 4. Such 2 digit combinations possible are.....
12,16,24,32,36,52,56,64,72,76.
At last two places, any one combination out of these 10 is
possible. For first two digits in the 4 digit number, the
possible combinations are 5*4=20
So there r 20*10=200 numbers divisible by 4.

Is This Answer Correct ?    71 Yes 7 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

A farmer built a fence around his 17 cows, in a square shaped region. He used 27 fence poles on each side of the square. How many poles did he need altogether?

1432


what is mean by aptitude test? how to write this paper?

1993


Find the unit digit of product of the prime number up to 50 ?

1124


Which of the following fractions is less than 1/3

789


The average of x and y is 6.5. if z=4,what is the average of x,y,z.

805






A plane starts from a place A , it goes 1000 kms south then 1000km east then 1000 km north and 1000km west, what is it distance from the starting place? ans.same starting place.

1158


Sir iam going to write exam for the post of Officers under training in APSRTC. Please send me the model papers to my mail ganjiramji@gmail.com

1829


What is the least number of squares marbles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?

801


if out of x bulbs y bulbs are broken;the % of non broken bulbs

878


A room is 30 X 12 X 12. a spider is on the middle of the smaller wall, 1 feet from the top, and a fly is on the middle of the opposite wall 1 feet from the bottom. what is the min distance required for the spider to crawl to the fly.

953


A salesperson by mistake multiplied a number and got the answer as 3, instead of dividing the number by 3.What is the answer he should have actually got?

988


A building with height D shadow upto G. What is the height of a neighbouring building with a shadow of C feet.

1051


X and Y are partners in a business. X invests 300 for 12 months and Y invested 600 for 6 months. If they gain a profit of 700 at the end of one year, what is X's share?

1552


What percent of 60 is 12?

912


hello..i hav cleared SBI written exm..i am a post graduate in english..wht type of questions they may ask me at the interview? plz help.

2021