Logical operator AND

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Age <- 15. What does (Age >= 13) AND (Age <= 19) evaluate to?

A TRUE

B FALSE

2. Which statement about AND is correct?

A TRUE when at least one condition is TRUE

B TRUE only when both conditions are TRUE

3. Age <- 11. What does (Age >= 13) AND (Age <= 19) evaluate to?

A FALSE

B TRUE

4. Which condition correctly checks that Mark is in the range 0 to 100?

A Mark >= 0 AND <= 100

B Mark >= 0 AND Mark <= 100

5. Score <- 50. What does (Score > 50) AND (Score < 100) evaluate to?

A FALSE

B TRUE

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Age >= 13 AND Age <= 19		AThe second condition is incomplete. Each side of AND must be a full condition, so Age is missing before <= 19.
2Score > 50 AND Score < 80 AND Passed = TRUE		BOR is used instead of AND. With OR almost every age is TRUE, so it does not check the 13 to 19 range.
3Check that a mark is in the range 0 to 100 using AND		CTRUE only when the age is from 13 to 19 inclusive, because both conditions must be TRUE
4If either condition is FALSE, the whole AND condition is FALSE		DIF 15 > 10 AND 4 > 9 THEN
5IF Age >= 13 AND <= 19 THEN		EA three-part AND that is TRUE only when all three conditions are TRUE
6IF Age >= 13 OR Age <= 19 THEN		FIF Mark >= 0 AND Mark <= 100 THEN

Definitions

AND

Fill in the Blanks

Complete each line of code by filling in the missing parts.

IF Age >= 13 ___ Age <= 19 THEN OUTPUT "Teenager" ENDIF

IF Age >= 13 AND Age __ 19 THEN OUTPUT "Teenager" ENDIF

IF Score >= 0 AND Score <= 100 THEN OUTPUT "Valid mark" _____

IF Age >= 13 AND Age <= __ THEN OUTPUT "Teenager" ENDIF

IF Num > 0 AND Num < 10 AND ___ <> 5 THEN OUTPUT "OK" ENDIF

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A IF Age>=13 AND Age>=19 THEN

B OUTPUT "Teen"

C ENDIF

Question 2

A INPUT Num

B Ok <- FALSE

C IF Num>=1 OR Num<=10 THEN

D Ok <- TRUE

E ENDIF

Question 3

A INPUT Age

B IF Age>=13 AND <=19 THEN

C OUTPUT "Teenager"

D ENDIF

Question 4

A INPUT Temp

B INPUT Rain

C IF Temp>20 AND Rain<>0 THEN

D OUTPUT "Warm and dry"

E ENDIF

Question 5

A INPUT A

B INPUT B

C INPUT C

D IF A>5 AND B>5 OR C>5 THEN

E OUTPUT "All above 5"

F ENDIF

Answer Key

Logical operator AND

Section A: Quick Questions

A — TRUE

B — TRUE only when both conditions are TRUE

A — FALSE

B — Mark >= 0 AND Mark <= 100

A — FALSE

Section B: Match the Pairs

Age >= 13 AND Age <= 19 → TRUE only when the age is from 13 to 19 inclusive, because both conditions must be TRUE

Score > 50 AND Score < 80 AND Passed = TRUE → A three-part AND that is TRUE only when all three conditions are TRUE

Check that a mark is in the range 0 to 100 using AND → IF Mark >= 0 AND Mark <= 100 THEN

If either condition is FALSE, the whole AND condition is FALSE → IF 15 > 10 AND 4 > 9 THEN

IF Age >= 13 AND <= 19 THEN → The second condition is incomplete. Each side of AND must be a full condition, so Age is missing before <= 19.

IF Age >= 13 OR Age <= 19 THEN → OR is used instead of AND. With OR almost every age is TRUE, so it does not check the 13 to 19 range.

Section C: Definitions

AND — AND joins two conditions and is TRUE only when both are TRUE, e.g. Age >= 13 AND Age <= 19. If either condition is FALSE, the whole condition is FALSE.

Section D: Fill in the Blanks

IF Age >= 13 AND Age <= 19 THEN
  OUTPUT "Teenager"
ENDIF

IF Age >= 13 AND Age <= 19 THEN
  OUTPUT "Teenager"
ENDIF

IF Score >= 0 AND Score <= 100 THEN
  OUTPUT "Valid mark"
ENDIF

IF Age >= 13 AND Age <= 19 THEN
  OUTPUT "Teenager"
ENDIF

IF Num > 0 AND Num < 10 AND Num <> 5 THEN
  OUTPUT "OK"
ENDIF

Section E: Spot the Error

A — The upper limit of the range should use <=. With Age>=19 the range check is wrong, so the correct condition is Age>=13 AND Age<=19.

C — A range check needs AND so both conditions must be TRUE. With OR every number passes. It should be IF Num>=1 AND Num<=10 THEN.

B — Each side of AND must be a complete condition. <=19 is missing the variable, so it should be Age<=19.

C — Warm and dry needs Rain to equal 0. Rain<>0 would be TRUE on a wet day. It should be Temp>20 AND Rain=0.

D — To check that all three values are above 5, every condition must be joined with AND. With OR, C>5 alone makes the condition TRUE. It should be A>5 AND B>5 AND C>5.