5 children are to be seated on one bench. In how many ways can it be done?
A). 120
B). 140
C). 124
D). 144
5 children are to be seated on a bench. In how many ways can it be done if the eldest child always sits in the middle?
A). 48
B). 12
C). 36
D). 24
How many 4letter code can be formed using the first 9 letters of the English alphabets, if no letter can be repeated?
A). 3024
B). 3036
C). 3021
D). 3034
In a party every person shakes hand with every other person. If there was a total of 210 handshakes in the party, find the no. of persons who were present in the party.
A). 20
B). 22
C). 21
D). 24
How many numbers of five digits can be formed with the digits 1, 3, 5, 7 and 9, no digit being repeated?
A). 120
B). 140
C). 160
D). 180