+ 3

# A logic puzzle . Can you solve it .

The average age of a familyβmade up of two parents with kidsβis 20. If you exclude one parent, who is 40, the average age drops to 15. How many kids are in the family?

29th Jun 2017, 12:39 AM
RZK 022
+ 2
import java.util.*; public class Program { public static void main(String[] args) { int age,avg1,avg2,n,child; Scanner sc=new Scanner(System.in); System.out.println("Enter age of a parent,avg1,avg2\n"); age=sc.nextInt(); avg1=sc.nextInt(); avg2=sc.nextInt(); n=(age-avg2)/(avg1-avg2); child=n-2; System.out.println("No. of child="+child); } } https://code.sololearn.com/cSb1Vef8gwd6/?ref=app
29th Jun 2017, 7:04 AM
Gaurav Sukhatme
+ 4
correct but you need to prove it by making a code
29th Jun 2017, 1:04 AM
RZK 022
+ 2
3 kids
29th Jun 2017, 1:03 AM
Nirmal Kumar Bhakat
+ 2
we can think this problem like this: the 40-aged parent give each of others 5 ages to reach 20, then he (or she) can give 4 times, including another parent, so there are 3 kids
29th Jun 2017, 5:03 AM
Flandre Scarlet
+ 2
writing it as a code: public int Solution(ave1, ave2, age){ return (age - ave1)/(ave1 - ave2) -1 }
29th Jun 2017, 5:07 AM
Flandre Scarlet
+ 1
In total there are 5 persons in the family . Total age = 5*20=100 When you remove one parent Total age of 4 persons = 60 avg=60Γ·4=15
29th Jun 2017, 1:04 AM
Nirmal Kumar Bhakat
+ 1
okay
29th Jun 2017, 1:05 AM
Nirmal Kumar Bhakat
+ 1
40 γγγ age of one parent n - Number of others members of The family n-1 number of children x γγ mean of n members of a family without 40 x=15 γγγ KNOWN (40+n*x)/(n+1) γγ mean of all members Solution γγ (40+n*x)/(n+1)=20 / *(n+1) 40+n*x=20*(n+1) 40+n*x= 20n+ 20 40 + n *15 = 20n + 20 / -15n-20 20= 5n / :5 4 = n / - second parent 3 = n-1 γγγ Number of children in a family n-1 γγγ Number of children γγγ 3 :)
1st Jul 2017, 5:56 AM
Rakowiecki Ryszard