Cognitive Reflection Test Problem Decomposition Strategies 2

Question 1

A widget and a box cost $2.20 together. The box costs $2.00 more than the widget. Decomposing this into two equations, how much does the widget cost?

Accepted Answer

$0.10

Answer

Widget = x, box = x + 2.00, so 2x + 2.00 = 2.20 gives x = $0.10.

Question 2

When decomposing a problem, what is the primary purpose of identifying independent sub-problems?

Accepted Answer

So they can be solved separately without affecting each other

Answer

Independent sub-problems can be solved in isolation because their solutions do not interfere.

Question 3

If 5 machines take 5 minutes to make 5 widgets, decomposing the rate, how long do 100 machines take to make 100 widgets?

Accepted Answer

5 minutes

Answer

Each machine makes one widget in 5 minutes, so 100 machines make 100 widgets in 5 minutes.

Question 4

Which step comes first in a top-down decomposition strategy?

Accepted Answer

Break the overall goal into major components

Answer

Top-down decomposition starts by splitting the overall goal into large components before detailing each.

Question 5

A lily pad patch doubles each day and covers the lake in 48 days. Decomposing the growth backward, on what day is it half covered?

Accepted Answer

Day 47

Answer

Since it doubles daily, the lake is half covered the day before full coverage, on day 47.

Cognitive Reflection Test Practice Test