a. Answer:
For this question we'll use the following method:
1. Let's subtract old value from new value
185$-160$ = -25$
The negative value implies that the price has decreased
2. Divide the result by the old value
25$/185$ = 0,1351
3. Convert this value to percentage:
0,1351 x 100 = 13,51%
Finally, by rounding to the nearest tenth:
13,5%
That means 13,5% decrease
b. Answer:
1. Let's subtract old value from new value
77$-56$ = 21$
The positive value implies that the price has increased
2. Divide the result by the old value
21$/77$ = 0,2727
3. Convert this value to percentage:
0,2727 x 100 = 27,3%
Finally, by rounding to the nearest tenth:
27,3%
That means 27,3% increase