A phone's price rises by 10% and the next month falls by 10%. Compared with the original price, the final price is:
Answer and explanation
Correct answer: C. 1% lower than the original (110 x 0.9 = 99 from a base of 100)
- Step 1: Start with 100: after a 10% rise it is 110. Step 2. A 10% fall of 110 removes 11, giving 99, which is 1% below 100. Answer: 1% lower than the original. Why not the others: The two percentages apply to different amounts, so they do not cancel; 10% lower or 1% higher ignore the changed base.
Practise more Problem Solving in Mathematics.
Free questions with an explanation for every one, and full timed ENLA Secondary Practice (Peru) mock tests.
More Problem Solving in Mathematics questions
- A school notebook costs S/ 4.50. How much do 6 of these notebooks cost in total?
- A rectangular garden is 12 m long and 7 m wide. What is its perimeter?
- The ages of five cousins are 4, 8, 6, 10 and 12 years. What is their mean age?
- Solve for : .
- A bag holds 3 red, 5 blue and 2 green marbles. One marble is drawn at random. What is the probability that it is red?
- A jacket priced at S/ 150 has a 20% discount. How much does the customer pay?