Identify the missing number at the end of the series.
4, 13, 21, 28, ?
Answer: D
EXplanation: The difference between the numbers in this series decreases by 1 each time: 9, 8, 7, etc. This will produce a difference of 6 between 28 and the next number in the series, which is therefore 34.
3, 9, 15, 21, ?
Answer: B
Explanation: The numbers in this series increase by 6 each time. Therefore the next number is 27.
In a survey, 3/16 of people said that they preferred to use self-service gas stations. 5/8 said that they preferred not to pump their own gas. The remaining 75 respondents said that they had no clear preference. How many people preferred self service?
Answer: A
Explanation: The proportion of the sample who preferred not to pump their own gas was 5/8 which is the same as 10/16. Add to this 3/16 which is the proportion of the sample that prefers to pump their own gas. This means that 13/16 of the people who replied to the survey expressed a preference. This means that 3/16 (or 75 people) did not. The question states that 3/16 of the sample preferred to use self service and we know that 3/16 = 75 people, therefore 75 people preferred self-service.
A total of 800 copies of a CD were sold. 60% were sold at 50% discount, 20% were sold at 30% discount and the remainder were sold at the full price of $8.95. What was the approximate total revenue in dollars?
Explanation: Of the 800 CDs sold: 20% or 160 were sold at $8.95 = $1432 20% or 160 were sold at $6.26 = $1001 60% or 480 were sold at $4.47 = $2145 Therefore the total revenue was $4578
Anna and John both drive to their new home 400 miles away. Anna drives the family car at an average speed of 60 mph. John drives the removal truck at an average speed of 50 mph. During the journey, Anna stops for a total of 1 hour and 20 minutes, John stops for half as long. What is the difference in minutes between their arrival times?
Answer: C
Explanation: If Anna covers 400 miles in at an average speed of 60 mph then she must have driven for a total of 6 hours and 40 minutes. If she stops for 1 hour and 20 minutes then her total journey time is 8 hours. If John covers 400 miles in at an average speed of 50 mph then he must have driven for a total of 8 hours. If he stops for 40 minutes then his total journey time is 8 hours and 40 minutes. Therefore there is a 40 minute difference in their arrival times.
