How many numbers of five digits can be formed by using 1, 2, 3, 4, 5, if 4 is necessarily taken at hundred's place and 2 is not allowed at unit's place. Repetition of numbers is not allowed.
Keeping 4 fixed at 100th position.
so there are 4 digits left.
Out of which 2 can not be placed in units place.
permutation of units place is 3.
permutation of 10000th place is 3
permutation of 1000th place is 2 .
permutation of 100 place is 1
permutation of 10th place = 1
So total permutation - 3 X 2 X 3 X 1 X 1= 18
6 boys and 8 men get a total wage of Rs 8000 in 4 days. 8 boys and 6 men get a total of Rs 6000 in 3 days.
The efficiency ratio of boy and a man respectively?
every no.given is divisible by its sum except -51.
133=1+3+3=7;133/7=19
171=1+7+1=9;171/9=19
-57=5+7=12=1+2=3;-57/3=19
-114=1+1+4=6;-114/6=19
38=3+8=11=1+1=2;38/2=19
-76=7+6=13=1+3=4;-76/4=19
95=9+5=14=1+4=5;95/5=19
whereas -51=5+1=6;& -51 is not divisible by 6.
so, the unmatched number will be -51.