Which expression represents reducing the fraction 40/100 to lowest terms?

Which expression represents reducing the fraction 40/100 to lowest terms?

• A. 4/10
• B. 8/20
• C. 5/10
• D. 2/5

Answer: (D)

Reducing a fraction to lowest terms means dividing numerator and denominator by their greatest common factor until nothing larger than 1 divides both. For 40/100, both numbers share the factor 20, so dividing top and bottom by 20 gives 40 ÷ 20 over 100 ÷ 20, which is 2/5. Since 2 and 5 have no common factors other than 1, 2/5 is already in lowest terms. The other expressions come from dividing by smaller common factors and can be reduced further (for example, 4/10 can be reduced by 2 to 2/5, 8/20 by 4 to 2/5, and 5/10 by 5 to 1/2). The fully reduced form that represents 40/100 is 2/5.

Reducing a fraction to lowest terms means dividing numerator and denominator by their greatest common factor until nothing larger than 1 divides both. For 40/100, both numbers share the factor 20, so dividing top and bottom by 20 gives 40 ÷ 20 over 100 ÷ 20, which is 2/5. Since 2 and 5 have no common factors other than 1, 2/5 is already in lowest terms. The other expressions come from dividing by smaller common factors and can be reduced further (for example, 4/10 can be reduced by 2 to 2/5, 8/20 by 4 to 2/5, and 5/10 by 5 to 1/2). The fully reduced form that represents 40/100 is 2/5.