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Sandra is 18 years older than Paulo. In 13 years, Sandra's age will be twice of Paulo's age. How old is Sandra now?

 Jul 8, 2020
 #1
avatar+92 
+1

First, we should assign variables.

Sandra’s Age = X + 18

Paolo’s Age = X

 

In 13 years, they will be:

 

(X + 18) + 13 = 2(x + 13)

 

X + 18 + 13 = 2x + 26

X + 31 = 2x + 26

X – 2x = 26 - 31

-x/-1 = -5/-1

X = 5

 

Therefore, Sandra is now:

 

Sandra’s Age = 5 + 18 = 23

 

Sandra is now 23 years old.

 

Checking their age:

 

23 (Sandra) – 5 (Paolo) = 18

 

smileysmileysmiley

 Jul 8, 2020
edited by Unicornrabbit  Jul 8, 2020
 #2
avatar+786 
+1

Let x be Paulo's current age and x+18 Sandra's. We form an equation of their ages in 13 years.

 

(x+18)+13=2(x+13)

x+31=2x+26

x=5

 

Sandra is x+18 so her age is 23 years old.

 Jul 8, 2020

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