WAEC Past Questions and Answers - Page 2340

11,696.

Miscellaneous file should be opened when

A.

the original file form document cannot be located

B.

there is insufficient correspondence from one source to justify opening new file

C.

there is insufficient time for the filing clerk to assemble relevant document to open a new file

D.

there are sufficient documents from various sources to justify opening a new file

Correct answer is C

No explanation has been provided for this answer.

11,697.

If 4x+2y=16 and 6x-2y=4 , find the value of (y-x).

A.

8

B.

2

C.

4

D.

6

Correct answer is B

Using elimination method:

4x+2y=16 * 6 --> 24x +12y=96 ... eqn iii

6x-2y=4  * 4 --> 24x - 8y = 16 ... eqn iv

Subtract eqn iv from iii

20y = 80

y = 4

Subst. y for 4 in 4x + 2y = 16

--> 4x + 2(4) = 16

--> 4x = 16 - 8

--> 4x = 8

--> x = 2

: The value of (y-x) is 4 - 2 = 2

11,698.

Simplify 2√7- 14/√7+7/√21

A.

\(\frac{√21}{21}\)

B.

7\(\frac{√21}{21}\)

C.

\(\frac{√21}{3}\)

D.

3√21

Correct answer is C

2√7-  14/√7 +7/√21

L.C.M is √21

\(\frac{√21 * 2√7  - √3 *14  + 7}{√21}\)

=\(\frac{2 * 7√3 - 14√3 + 7}{√21}\)

= \(\frac{14√3 - 14√3 + 7}{√21}\)

=\(\frac{7}{√21}\)

or 

\(\frac{7 \times √21}{√21 \times √21}\) 

= \(\frac{7 \times √21}{21}\) or  \(\frac{√21}{3}\) 

11,699.

The circumference of a circular track is 9km. A cyclist rides round it a number of times and stops after covering a distance of 302km. How far is the cyclist from the starting point?

A.

5km

B.

6km

C.

7km

D.

3km

Correct answer is A

Circumference of the circular track = 9km

Distance covered = 302km

Number of complete circles or revolutions from the starting point = 302/9 =33 circles and additional 5km.

So, the distance of the cyclist from the starting point would be 5km

11,700.

If 16 * 2\(^{(x + 1)}\) = 4\(^x\) * 8\(^{(1 - x)}\), find the value of x.

A.

-4

B.

4

C.

1

D.

-1

Correct answer is D

16 * 2\(^{(x + 1)}\) = 4\(^x\) * 8\(^{(1 - x)}\) 

= 2\(^4\) * 2\(^{(x + 1)}\) = 2\(^{2x}\) * 2\(^{3(1 - x)}\)

--> 4 + x + 1 = 2x + 3 - 3x

collect like terms

--> x - 2x + 3x = 3 - 1 - 4

--> 2x = -2

--> x = -1