Four 4’s

Logic Level 1

Can you make an equation by using only 4,4,4,4 which the answer will be 20?

You can use the 4 standard arithmetic operations.

Yes No

Rui Chang Lu by Rui Chang Lu , 15, Oman

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3 solutions

4 × ( 4 ÷ 4 + 4 ) = 4 × 5 = 20 \large 4 \times (4 \div 4 + 4) = 4 \times 5 = 20 .

2 Helpful 0 Interesting 0 Brilliant 0 Confused
Mohammad Khaza
Nov 6, 2017

there are so many ways to do that:

1. ( 4 4 + 4 ) × 4 = 20 \color{#3D99F6}({\frac{4}{4}+4})\times 4=20

2. 4 ! − 4 × 4 4 = 20 \color{#D61F06}4!-\frac{4 \times 4}{4}=20

3. 4 ! − 4 − 4 + 4 = 20 \color{#20A900}4!-4-4+4=20 ..etc

1 Helpful 0 Interesting 0 Brilliant 0 Confused
André Hucek
Oct 30, 2017

4 □ 4 □ 4 □ 4 = 20 = 4 ! − 4 − 4 + 4 = 20 = 24 − 4 = 20 4~ \square~ 4~ \square~ 4~ \square~ 4~ = 20 \\ = 4! - 4 - 4 + 4 = 20 \\ = 24 - 4 = \ \boxed{20}

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