self Maths Puzzle

The population of town was 24000. If males increase by 6% and females by 9%, it becomes 25620. Number of males and females are
1.18000, 6000
2.19000, 5000
3.16000, 8000
4.20000, 4000

Read Solution (Total 3)

18000 male and 6000 females
25620-24000=1620
now
18000*6/100+6000*9/100=1080+540=1620
12 years agoHelpfull: Yes(2) No(2)

ans is option 1
12 years agoHelpfull: Yes(2) No(2)
M+F=24000--->Eqn 1
New population-Old population= 25620-24000=1620
So M*6/100+F*9/100=1620
6M+9F=162000--->Eqn 2
Solve Equation 1 & 2
Eqn 1 *6--->6M+6F=144000
Eqn 2 --->6M+9F=162000
On solving 3F=18000

Therefore F= 6000, Substitue F value in Eqn 1 or 2 to get M
M+6000=24000
M=18000
Option 1. 18000, 6000
11 years agoHelpfull: Yes(2) No(0)

self Other Question

This guy living on the 20th floor in an apartment building got up early each morning to go to work in a downtown store. He always went into the elevator on the 20th floor and rode down to the entrance (1st floor). When he came home he always rode the elevator from the entrance and up to the 8th floor. He walked out of the elevator and walked the stairs up to his apartment on the 20th floor.

Why didn't he take the elevator all the way up to his apartment? abcde is a 5-digit number such that abcde*4=edcba.....a,b,c,d,e are different digits...find abcde?