Question

Which sentence matches the mathematical equation? p-0.40p=0.60p
a. Decreased by 40 is the same as multiply by 60
b. Decreased by 40 is the same as increase by 60
c. Decreased by 40% is the same as multiply by 60%
d. Decreased by 40% is the same as increased by 60%

Answer 1

p-0.40p = 0.60p

C. Decrease by 40% is the same as multiply by 60%.

Assume that p = 10

10 - 0.40(10) = 0.60(10)
10 - 4 = 6
6 = 6

Based on the above assumption. 40% of 10 is 4 ; and 60% of 10 is 6. So, 10 less 4(40% of 10) is equal to 6 (60% of 10). 

Percentage is used because 0.40 and 0.60 will be multiplied with 100% to get the equivalent percentage 0.40 x 100% = 40% ; 0.60 x 100% = 60%