Cognitive Reflection Test Classic Numerical Reasoning Problems 2 — Questions and Answers
Question 1: A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
- $0.05 (Correct answer)
- $0.10
- $0.15
- $1.00
Correct answer: $0.05
If the ball is $0.05, the bat is $1.05, totaling $1.10 with the correct $1.00 difference.
Question 2: If 5 machines take 5 minutes to make 5 widgets, how long would 100 machines take to make 100 widgets?
- 5 minutes (Correct answer)
- 20 minutes
- 100 minutes
- 500 minutes
Correct answer: 5 minutes
Each machine makes 1 widget in 5 minutes, so 100 machines make 100 widgets in the same 5 minutes.
Question 3: A lily pad patch doubles in size every day and covers the whole lake in 48 days. How long to cover half the lake?
- 24 days
- 47 days (Correct answer)
- 36 days
- 12 days
Correct answer: 47 days
Since it doubles daily, the lake is half-covered the day before it is fully covered, on day 47.
Question 4: A pencil and eraser cost $1.20 together. The pencil costs $1.00 more than the eraser. What does the eraser cost?
- $0.20
- $0.10 (Correct answer)
- $0.15
- $0.05
Correct answer: $0.10
The eraser is $0.10 and the pencil is $1.10, giving the $1.00 difference and $1.20 total.
Question 5: If it takes 3 painters 3 hours to paint 3 fences, how long for 9 painters to paint 9 fences?
- 3 hours (Correct answer)
- 9 hours
- 1 hour
- 27 hours
Correct answer: 3 hours
Each painter paints one fence in 3 hours, so 9 painters paint 9 fences in 3 hours.
Question 6: Bacteria in a jar double every minute and fill the jar in 60 minutes. When is the jar half full?
- 30 minutes
- 59 minutes (Correct answer)
- 45 minutes
- 58 minutes
Correct answer: 59 minutes
Doubling each minute means the jar is half full one minute before it is full, at 59 minutes.
Question 7: A shirt and a tie cost $2.20 together. The shirt costs $2.00 more than the tie. How much is the tie?
- $0.20
- $0.10 (Correct answer)
- $0.15
- $0.22
Correct answer: $0.10
The tie is $0.10 and the shirt is $2.10, matching the $2.00 difference and $2.20 total.
Cognitive Reflection Test Classic Numerical Reasoning Problems 2
A bat and a ball cost $1.10 in total.
The bat costs $1.00 more than the ball.
How much does the ball cost?