IQ TEST: Math, Percentages, Markdowns, Discounts, Original, discounted Price, Ratio, Proportion

1. The ratio of two numbers is 1:4, if the smaller number is increased by 7, the ratio becomes 1:2. Find the two numbers.

find:

x = smaller number (based on 1:4 ratio)

4x = bigger number (based on 1:4 ratio)

solution:

(x + 7)/4x = 1/2

4x = 2x + 14

2x = 14

x = 7

4x = 4 * 7 = 28



2. A certain product has been marked down twice. The first was 20% and the second 25%. If the original price was $100, what is the final price after the two markdowns?

find:

x = final price


solution:

after first mark down of 20%

Price = 100 * 0.80 = 80


after second mark down of 25%

x = 80 * 0.75 = 60


3. The original price was $100. A discount of 10% has been offered, then the price went back to the original price. What is the percentage of increase with respect to the discounted price?

find:

x = percent of increase with respect to the discounted price

solution:

after 10% discount

discounted price = 100 * 0.90 = 90


to go back to original price

increase = 100 - 90 = 10


x = (increase/discounted price) * 100%

x = 10/90 * 100%

x = 1/9 * 100%

x = 11.11% ---> [ 1/9 is repeating 0.1111111111111111111111111111 ]