WAEC Past Questions and Answers - Page 1143

5,711.

Which of the following errors would affect the agreement of the agreement of the trial balance totals?

A.

Commission

B.

Omission

C.

Single entry

D.

Original entry

Correct answer is C

No explanation has been provided for this answer.

5,712.

Two forces (2i - 5j)N and (-3i + 4j)N act on a body of mass 5kg. Find in \(ms^{-2}\), the magnitude of the acceleration of the body.

A.

\(\frac{\sqrt{2}}{5}\)

B.

\(5\sqrt{2}\)

C.

\(2\sqrt{5}\)

D.

\(\frac{5\sqrt{2}}{2}\)

Correct answer is A

\(F = F_{1} + F_{2}\)

\((2i - 5j) + (-3i + 4j) = (-i - j)\)

\(F = ma \implies (-1, -1) = 5a\)

\(a = (-\frac{1}{5}, -\frac{1}{5})\)

\(|a| = \sqrt{(\frac{-1}{5})^2 + (\frac{-1}{5})^2} = \sqrt{2}{25}\)

\(|a| = \frac{\sqrt{2}}{5} ms^{-2}\)

5,713.

Yomi was asked to label four seats S, R, P, Q. What is the probability he labelled them in alphabetical order?

A.

\(\frac{1}{24}\)

B.

\(\frac{1}{6}\)

C.

\(\frac{2}{13}\)

D.

\(\frac{1}{4}\)

Correct answer is A

The number of arrangements for the 4 letters = \(^{4}P_{4} = \frac{4!}{(4 - 4)!}\)

\(4! = 24\)

Alphabetical order is just 1 of the arrangements for the letters 

= \(\frac{1}{24}\)

5,715.

Find the direction cosines of the vector \(4i - 3j\).

A.

\(\frac{9}{10}, \frac{27}{10}\)

B.

\(\frac{17}{27}, -\frac{17}{27}\)

C.

\(\frac{4}{5}, -\frac{3}{5}\)

D.

\(\frac{4}{7}, \frac{-3}{7}\)

Correct answer is C

Given \(V = xi +yj\), the direction cosines are \(\frac{x}{|V|}, \frac{y}{|V|}\).

\(|4i - 3j| = \sqrt{4^{2} + (-3)^{2}} = \sqrt{25} = 5\)

Direction cosines = \(\frac{4}{5}, \frac{-3}{5}\).