Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
COMPUTER SCIENCE
Paper 2
Friday 15 June 2018 Morning Time allowed: 2 hours 30 minutes
Materials For Examiner’s Use
For this paper you must have:
Question Mark
• a calculator.
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do not write outside 5
the box around each page or on blank pages. 6
• Do all rough work in this book. Cross through any work you do not want to be
marked. 7
8
Information 9
• The marks for questions are shown in brackets.
10
• The maximum mark for this paper is 100.
11
Advice 12
• In some questions you are required to indicate your answer by completely 13
shading a lozenge alongside the appropriate answer as shown.
• If you want to change your answer you must cross out your original answer as 14
shown. 15
• If you wish to return to an answer previously crossed out, ring the answer
TOTAL
you now wish to select as shown.
*jun187517201*
IB/M/Jun18/E10 7517/2
, 2
Do not write
Answer all questions. outside the
box
0 1 . 1 Shade one lozenge to indicate which of the unsigned numbers listed in
Table 1 has the largest value.
Table 1
Number Number Largest value
base (shade one)
Binary 101101001
Hexadecimal 30A
Decimal 396
[1 mark]
Questions 01.2 and 01.3 use a normalised floating point representation with a 7-bit
mantissa and a 5-bit exponent, both stored using two’s complement.
The following is a floating point representation of a number:
0 1 0 1 1 0 0 1 1 1 0 1
Mantissa Exponent
0 1 . 2 Calculate the decimal equivalent of the number. You must show your working.
[2 marks]
Answer
*02*
IB/M/Jun18/7517/2
, 3
Do not write
outside the
0 1 . 3 Write the normalised floating point representation of the decimal value -608 in the box
boxes below. You must show your working.
[3 marks]
Answer
6
Mantissa Exponent
Turn over for the next question
Turn over ►
*03*
IB/M/Jun18/7517/2
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
COMPUTER SCIENCE
Paper 2
Friday 15 June 2018 Morning Time allowed: 2 hours 30 minutes
Materials For Examiner’s Use
For this paper you must have:
Question Mark
• a calculator.
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do not write outside 5
the box around each page or on blank pages. 6
• Do all rough work in this book. Cross through any work you do not want to be
marked. 7
8
Information 9
• The marks for questions are shown in brackets.
10
• The maximum mark for this paper is 100.
11
Advice 12
• In some questions you are required to indicate your answer by completely 13
shading a lozenge alongside the appropriate answer as shown.
• If you want to change your answer you must cross out your original answer as 14
shown. 15
• If you wish to return to an answer previously crossed out, ring the answer
TOTAL
you now wish to select as shown.
*jun187517201*
IB/M/Jun18/E10 7517/2
, 2
Do not write
Answer all questions. outside the
box
0 1 . 1 Shade one lozenge to indicate which of the unsigned numbers listed in
Table 1 has the largest value.
Table 1
Number Number Largest value
base (shade one)
Binary 101101001
Hexadecimal 30A
Decimal 396
[1 mark]
Questions 01.2 and 01.3 use a normalised floating point representation with a 7-bit
mantissa and a 5-bit exponent, both stored using two’s complement.
The following is a floating point representation of a number:
0 1 0 1 1 0 0 1 1 1 0 1
Mantissa Exponent
0 1 . 2 Calculate the decimal equivalent of the number. You must show your working.
[2 marks]
Answer
*02*
IB/M/Jun18/7517/2
, 3
Do not write
outside the
0 1 . 3 Write the normalised floating point representation of the decimal value -608 in the box
boxes below. You must show your working.
[3 marks]
Answer
6
Mantissa Exponent
Turn over for the next question
Turn over ►
*03*
IB/M/Jun18/7517/2
