Question 1141630
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4/9 of 36 is 16; so he originally had 16 games and 20 other apps.<br>
He adds more games and no other apps, after which 2/3 of the apps are games.  So<br>
{{{(16+x)/(36+x) = 2/3}}}<br>
Solve using basic algebra....<br>
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Or try solving using logical reasoning instead of formal algebra; something like this:<br>
There are 20 apps on his phone that are not games.  After he adds the additional game apps, those 20 other apps are now 1/3 of the total (because 2/3 are now games).<br>
1/3 of the total being 20 apps means the total number of apps is now 3*20 = 60.  And since he originally had a total of 36 apps, the number of game apps he added was 60-36 = 24.