Correct Answer: D. 60

Explanation

Let number of children's ticket at N250.00 each = \(x\)

∴ Number of adult tickets at ?520.00 each = 5\(x\)

Then,

Total amount of money received from children's tickets = 250\(x\)

Total amount of money received from adult tickets = 520(5\(x\))

⇒ 250\(x\) + 520(5\(x\)) = 171,000

⇒ 250\(x\) + 2600\(x\) = 171,000

⇒ 2850\(x\) = 171,000

⇒ \(x = \frac{171,000}{2850} = 60\)

∴ 60 tickets were sold at N250.00 and 300 tickets were sold at N520.00

Correct Answer: B. 8.8 x 10³m

Explanation

R = \(\frac{4eL}{\pid^2}\)

L = \(\frac{R\pid^2}{4e}\)

= \(\frac{21 \times 3.14(4 \times 10^{-3})^2}{4 \times 3.0 x 10^{-8}}\)

= 8.8 x 10³m

Explanation

The functions or roles of the Assembly of Heads of State and Governments of the Organization of African Unity (0.A.U) are: (i) It acts as the highest decision-making organ of the O.A.U.

(ii) It discusses matters of common interest of member states.

(iii) It coordinates and harmonises the general policies of the organisation.

(iv) It appoints the important officers of the organisation such as the Secretary General.

(v) It has power to establish specialized commissions.

(vi) It examines and reviews the structure, composition and functions of all other organs and specialized agencies of the organisation.

(vii) It considers reports from the secretariat.

(viii) It appoints adhoc committees to settle disputes involving member states.

(ix) It decides on the admission of new members.

(x) It considers and approves proposals for amendments of the charter of the organisation.

(xi) It approves the regulations governing the function and conditions of services of the Administrative Secretary General, his assistants and other staff.

Explanation

(a)(i)

(ii) Application of electrolysis

- For purification of elements e.g. copper, gold, silver

- For protection of metals from corrosion / electroplating

- For manufacture of chemicals e.g. NaOH, NaCIO\(_{3}\)

- For extraction of metals e.g Al, Ca, K, Na, Mg, etc.

(iii) Electrolysis of dilute NaCl(\(^{aq}\)) using carbon electrodes.

At the Cathode H\(^{+}\) + e\(^-\) —> H

H + H —> H\(^2\) Or 2H\(^{+}\) + 2e\(^-\) —> H\(_2\)

At the anode OH\(^-\) —> OH + e\(^-\)

or 4OH\(^- \) ---> 2H\(^2\)O + O\(_2\) Or 4OH\(^-\) —> 2H\(_2\)O + O\(_2\) + 4e\(^{-}\).

(b)(i) An electrochemical cell is a device for producing an electric current by chemical reaction.

(ii) Examples of primary cell: Daniell cell, Leclanche cell, cadmin / weston mercury cell.

(iii) Mg + Fe\(^{2+}\) --> Mg\(^{2+}\) + Fe ;

Half cell reactions: Mg --> Mg\(^{2+}\) + 2e\(^{-}\)

Fe\(^{2+}\) + 2e\(^-\) --> Fe or Mg - 2e\(^-\) --> Mg\(^{2+}\)

(c)(i) To calculate the quantity of electricity produced by a current of 0.72 A in 3 hours 20 mins.

Q = It

t = (3 x 60 + 20) min x 60 sec = 12000 Sec.

Q = (0.72 x 12000) C = 8640 C.

(ii) If 1 dm\(^3\) of gas was evolved at the cathode during electrolysis of acidified water, volume of gas evolved at the anode will be 0.5 dm\(^3\) or 500cm\(^3\).

(d)(i) Calculation of excess CuO if 20g was warmed with 0.05 mole H\(_2\)SO\(_4\). CuO + H\(_2\)SO\(_4\) --> CuSO\(_4\) + H\(_2\)O. From the equation 0.05 mole of H\(_2\)SO\(_4\) reacts with 0.05 mole of CuO.

Molar mass of CuO = 64 + 16 = 80g.

Hence 0.05 mole CuO = (80 x 0.05)g = 4.0g.

Mass of CuO in excess = 20 - 4 = 16g.

(ii) Type of reaction involved in the reaction in (d)(i) is neutralisation / acid - base reaction.

Correct Answer: D. #180,000

Correct Answer: B. (2y - 3x) (y - 6x)

Correct Answer: D. 10

Explanation

\(p(blue) = \frac{\text{no of blue balls}}{\text{total no of balls}}\)

= \(\frac{2}{3} = \frac{k}{k + 5}\)

\(3k = 2(k + 5) \implies 3k = 2k + 10\)

\(3k - 2k = k = 10\)

Correct Answer: B. inspiration from Allah

Explanation

Hijrah, (Arabic: Migration or Emigration) the Prophet Muhammad's migration (622 CE) from Mecca to Yathrib (Medina) upon invitation in order to escape persecution. Uthman Dan Fodio's appeal to justice and morality rallied the outcasts of Hausa society. He found his followers among the Fulbe and Fulani. The Fulbe and Fulani were primarily cattle pastoralists. These pastoralist communities were led by the clerics living in rural communities who were Fulfude speakers and closely connected to the pastoralists. The Fulani would later hold the most important offices of the new states. Hausa peasants, runaway slaves, itinerant preachers, and others also responded to Uthman's preaching. His jihad served to integrate a number of peoples into a single religio-political movement. They were both inspired by Allah.

Correct Answer: A. increased financial activities

Correct Answer: C. ensuring Egyptian independence

Explanation

Egypt, who finally got her independence in 1922 in her 19th century was seen fighting colonialism through her nationalists to ensure independence.