The total of three sisters' ages is 39. Dina is is half as old as Michelle and 3 years younger than Juliette. How old are the sisters?

Question

Nathan Axel · Accepted Answer

Dina #=9# years old
Michelle #= 18# years old
Juliette #=12# years old

Let Michelle's age be#2x# Given Dina is half as old as Michelle, #=># Dina's age #=x# Given Dina is #3# years younger than Juliette, #=># Juliette'a age #=x+3# Given the sum of the three sisters' age is #39#, #=> 2x+x+x+3=39# #=> 4x+3=39# #=> 4x=39-3=36# #x=36/4=9# Hence, Dina's age #=x=9# Michelle's age #=2x=2*9=18# Juliette's age #=x+3=9+3=12# Check : #9+18+12=39#, OK

Genesis Allen · Answer

undefined Let Michelle's age be M, Juliette's age be J, and Dina's age be D.

We have the following information:
1. M + J + D = 39 (total of three sisters' ages is 39)
2. D = 0.5M (Dina is half as old as Michelle)
3. D = J - 3 (Dina is 3 years younger than Juliette)

From equation 2, we can substitute D = 0.5M into equation 3 to get:
0.5M = J - 3

Solving for J in terms of M:
J = 0.5M + 3

Now, substitute the expression for J into the total age equation:
M + (0.5M + 3) + 0.5M = 39
2M + 3 = 39
2M = 36
M = 18

Now that we know Michelle's age is 18, we can find the ages of the other sisters:
D = 0.5 * 18 = 9 (Dina's age)
J = 0.5 * 18 + 3 = 9 + 3 = 12 (Juliette's age)

So, Michelle is 18 years old, Juliette is 12 years old, and Dina is 9 years old.