Use Table 1 to answer the following question.
Table 1: TableStudent
Reg No | House |
Age |
18/001 | Yellow | 14 |
18/002 | Blue | 15 |
18/003 | Yellow | 15 |
The attributes in Table 1 are
Yellow, Blue, Yellow
14, 15, 15
Reg. No, House, Age
18/001, 18/002, 18/003
Correct answer is C
The attributes in Table 1 are Reg. No, House, and Age.
An attribute is a single piece of data about an entity. In Table 1, each row represents a student entity. The Reg. No, House, and Age columns represent the attributes of the student entity.
The values in the Reg. No column are unique, so the Reg. No column is the primary key of the table. The House and Age columns are not unique, so they cannot be used as primary keys.
The other values in the table are the data for the attributes. For example, the value "18/001" in the Reg. No column is the data for the Reg. No attribute of the first student entity.
Use Table 1 to answer the following question.
Table 1: TableStudent
Reg No | House |
Age |
18/001 | Yellow | 14 |
18/002 | Blue | 15 |
18/003 | Yellow | 15 |
Columns 2 and 3 in Table 1 cannot be used as primary key because both fields contain
Different datatypes
Duplicate values
The same datatype
Only strings and numbers respectively
Correct answer is B
Columns 2 and 3 in Table 1 cannot be used as a primary key because both fields contain duplicate values.
A primary key is a unique identifier for each record in a database table. It ensures that each record has a distinct value, allowing for efficient data retrieval and maintaining data integrity. In the given TableStudent, the "House" column (Column 2) and the "Age" column (Column 3) both contain duplicate values. For example, the House column has two records with the value "Yellow" and the Age column has two records with the value "15". Since a primary key must have unique values, neither of these columns can be used as the primary key.
Figure 3 is a Microsoft Excel Worksheet. Use it to answer questions 20 and 21.
A | B | C | D | E | |
1 | IDENTICATION NUMBER | BASIC SALARY (N) | TOTAL ALLOWANCE (N) | TOTAL DEDUCTION (N) |
NET SALARY (N) |
2 | WASC/LPT/001 | 800000 | 60000 | 40000 | 820000 |
3 | WASC/LPT/002 | 700000 | 40000 | 20000 | 720000 |
4 | WASC/LPT/003 | 300000 | 10000 | 5000 | 305000 |
5 | WASC/LPT/004 | 400000 | 20000 | 10000 | 410000 |
Figure 3
What formula will calculate the total number of individuals who earn less than ₦500,000 from the table as shown in Figure 3?
COUNT(E2:E5
COUNT(E2:E5)
COUNTA(E2:E5)
COUNTIF(E2:E5
Correct answer is D
The formula that will calculate the total number of individuals who earn less than ₦500,000 from the table as shown in Figure 3 is COUNTIF(E2:E5, "< 500,000").
The COUNTIF function counts the number of cells that contain a specific value in a range. In this case, we want to count the number of cells in the E column that contain a value less than ₦500,000. The E column contains the net salaries of the individuals. Therefore, the COUNTIF function will return the total number of individuals who earn less than ₦500,000.
Figure 3 is a Microsoft Excel Worksheet. Use it to answer questions 20 and 21.
A | B | C | D | E | |
1 | IDENTICATION NUMBER | BASIC SALARY (N) | TOTAL ALLOWANCE (N) | TOTAL DEDUCTION (N) |
NET SALARY (N) |
2 | WASC/LPT/001 | 800000 | 60000 | 40000 | 820000 |
3 | WASC/LPT/002 | 700000 | 40000 | 20000 | 720000 |
4 | WASC/LPT/003 | 300000 | 10000 | 5000 | 305000 |
5 | WASC/LPT/004 | 400000 | 20000 | 10000 | 410000 |
Figure 3
What formula will correctly display the total number of individuals involved in the computation as shown in Figure 3?
COUNT(A2:A5)
COUNTIF(A2:A5)
COUNTA(A2:A5)
SUM(A2:A5)
Correct answer is C
The formula that will correctly display the total number of individuals involved in the computation as shown in Figure 3 is COUNTA(A2:A5).
The COUNTA function counts the number of cells that are not empty in a range. In this case, we want to count the number of cells in the A column that are not empty. The A column contains the identification numbers of the individuals involved in the computation. Therefore, the COUNTA function will return the total number of individuals involved in the computation.
The other formulas mentioned are:
COUNT: This function counts the number of cells that contain numbers in a range.
COUNTIF: This function counts the number of cells that contain a specific value in a range.
SUM: This function sums the values in a range.
In this case, we do not want to count the number of cells that contain numbers or the number of cells that contain a specific value. We want to count the number of cells that are not empty. Therefore, the COUNTA function is the most appropriate function to use.
S/N | A | B | C | D | E | F | G | H |
1 | STAFF | DAYS | ITEMS SALES (N) | ITEMS SALES (N) | ITEMS SALES (N) | ITEMS SALES (N) | ITEMS SALES (N) |
ITEMS SALES (N) |
2 | JOY | MON | 208 | 300 | 500 | 400 | 300 | 158 |
3 | AKIN | TUE | 300 | 200 | 500 | 400 | 200 | 200 |
4 | KEN | WED | 400 | 300 | 400 | 500 | 100 | 300 |
Figure 3
The highest sale by Joy is recorded in cell
F1
B4
B4
E2
Correct answer is D
No explanation has been provided for this answer.