Asign at a store said all purchases were 40% off. which is another way this nuber could have been written a .1/5 off b.1/4 off c. 3/10 off d.2/5 off

To concert a percentage into a fraction, first convert it into a decimal. To change a percentage into a decimal, you have to take away the percentage sign and move the decimal point two places to the left. Thus, 40% = 0.40 = 0.4 Now, to change the decimal into a fraction, you multiply both the numerator and the denominator (1) by 10. 0.4/1 = 4/10 However, in this case the fraction is in simplest form. To simplify a fraction, you have to divide the numerator and the denominator by the GCF, which in this case is 2. 4/10 = 2/5 Therefore, your answer is D. 2/5 off.