Input–Output Quiz: Machine Input Reasoning Practice

Spoilers! These are the Starter quiz’s answers. Easy, Medium, Hard and Mixed rounds show their own answers when you finish.

1. A machine arranges numbers. In each step, the smallest number not yet arranged is moved to the left, just after the numbers already arranged; the other numbers keep their order. Input: 45 12 78 33 90 21. Which of these is Step II?

   • 12 21 45 33 78 90
   • 12 21 45 78 33 90
   • 12 45 21 78 33 90
   • 12 21 33 45 78 90

   Answer: 12 21 45 78 33 90. Step I moves 12 to the front: 12 45 78 33 90 21. Step II moves 21 next to it: 12 21 45 78 33 90.

2. A machine arranges numbers. In each step, the smallest number not yet arranged is moved to the left, just after the numbers already arranged; the other numbers keep their order. Input: 64 29 51 17 83 40. What is Step III?

   • 17 29 40 51 64 83
   • 17 29 64 51 83 40
   • 17 29 40 64 51 83
   • 17 40 29 64 51 83

   Answer: 17 29 40 64 51 83. Step I: 17 64 29 51 83 40. Step II: 17 29 64 51 83 40. Step III brings 40 forward: 17 29 40 64 51 83.

3. A machine changes every number in each step: an odd number is increased by 3 and an even number is halved. Input: 14 9 22 7. What is Step III?

   • 5 3 7 8
   • 10 6 14 5
   • 5 3 14 8
   • 5 6 7 8

   Answer: 5 3 7 8. Step I: 7 12 11 10. Step II: 10 6 14 5. Step III: 10 becomes 5, 6 becomes 3, 14 becomes 7 and 5 becomes 8, giving 5 3 7 8.

4. A machine changes every number in each step: an odd number is increased by 3 and an even number is halved. Input: 36 11 40 5. What is the sum of the numbers in Step II?

   • 29
   • 60
   • 30
   • 34

   Answer: 30. Step I: 18 14 20 8. Step II: 9 7 10 4. Their sum is 30.

5. In each step, a machine places the word that comes first in dictionary order among the words not yet arranged, followed by the smallest number not yet arranged, just after the elements already arranged; everything else keeps its order. Example — Input: pen 52 cat 19 rat 74 ant 36. Step I: ant 19 pen 52 cat rat 74 36. Step II: ant 19 cat 36 pen 52 rat 74. For the input 'fig 81 bus 27 owl 45 dot 63', what is Step II?

   • bus 27 dot 45 fig 63 owl 81
   • bus 27 fig 81 owl 45 dot 63
   • bus 27 dot 45 fig 81 owl 63
   • bus 27 dot 63 fig 81 owl 45

   Answer: bus 27 dot 45 fig 81 owl 63. Step I places bus and 27: bus 27 fig 81 owl 45 dot 63. Step II places dot and 45 next: bus 27 dot 45 fig 81 owl 63.

6. In each step, a machine places the word that comes first in dictionary order among the words not yet arranged, followed by the smallest number not yet arranged, just after the elements already arranged; everything else keeps its order. Input: lamp 38 desk 91 cup 14 rug 57 bin 72. How many steps are needed to complete the arrangement?

   • 4
   • 5
   • 6
   • 3

   Answer: 5. The steps place bin 14, cup 38, desk 57, lamp 72 and finally rug 91, each changing the line: bin 14 cup 38 desk 57 lamp 72 rug 91 appears in Step V.

7. In each step, a machine moves the shortest word not yet arranged (if two are equally long, the one first in dictionary order) to the left, just after the words already arranged; other words keep their order. Input: window apple of tree sky banana. What is Step III?

   • of sky tree apple window banana
   • of sky window apple tree banana
   • of sky tree apple banana window
   • of sky tree window apple banana

   Answer: of sky tree window apple banana. Step I: of window apple tree sky banana. Step II: of sky window apple tree banana. Step III brings tree forward: of sky tree window apple banana.

8. In each step, a machine moves the shortest word not yet arranged (if two are equally long, the one first in dictionary order) to the left, just after the words already arranged; other words keep their order. Input: river is gold a planet star. How many steps are needed to complete the arrangement?

   • 4
   • 5
   • 3
   • 6

   Answer: 4. Step I: a river is gold planet star. Step II: a is river gold planet star. Step III: a is gold river planet star. Step IV: a is gold star river planet — now complete.

9. In each step, a machine moves the largest number not yet arranged to the right end of the unarranged part and the smallest number not yet arranged to its left end; the others keep their order. Input: 56 23 87 41 15 69 32 74. Which number is 4th from the left in Step III?

   • 41
   • 32
   • 69
   • 56

   Answer: 56. Step I: 15 56 23 41 69 32 74 87. Step II: 15 23 56 41 69 32 74 87. Step III: 15 23 32 56 41 69 74 87. The 4th number is 56.

10. In each step, a machine moves the largest number not yet arranged to the right end of the unarranged part and the smallest number not yet arranged to its left end; the others keep their order. Input: 38 92 17 64 29 85. What is Step I?

    • 17 38 64 29 85 92
    • 17 92 38 64 29 85
    • 38 17 64 29 85 92
    • 17 38 29 64 85 92

    Answer: 17 38 64 29 85 92. 92 moves to the right end and 17 to the left end, while 38, 64, 29 and 85 keep their order: 17 38 64 29 85 92.