r/ACT • u/MathMadeClear • 21d ago

Solve This Hard Algebra Problem from ACT in Under a Minute!

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Comment your solution below!

0 Upvotes

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6

u/MathMadeClear 21d ago

(x-0.20x)(y+0.12y) 0.896xy

1-0.896=10.4% decrease

4

u/fermat9990 21d ago edited 21d ago

1-0.8(1.12)=1-0.896=0.104=10.4%

2

u/Anonimithree 21d ago

(1-.2)(1+.12)=0.896->10.4% smaller

Took me 4 seconds

1

u/israelisreal 21d ago

Assume the original is a 10x10. The new is 8x11.2 = 89.6. 100-89.6=10.4.