Explanation

(a) Present ages of a father and his son are in the ratio 10 : 3.

Let the sum of their ages be x.

The son's age = 15 years = \(\frac{3}{13} \times x = 15\)

\(x = \frac{15 \times 13}{3} = 65\)

\(\therefore\) The Father's present age = 65 - 15 = 50 years.

In z years time, the ratio of their ages = 2 : 1

\(\frac{50 + z}{15 + z} = \frac{2}{1}\)

\(\implies 50 + z = 2(15 + z)\)

\(50 + z = 30 + 2z \implies 50 - 30 = 2z - z\)

\(20 = z\)

Therefore, in 20 years' time, the ratio of their age will be 2 : 1.

(b) \(\frac{x + y + z}{3} = 6 \implies x + y + z = 18 .... (1)\)

\(\frac{x + y + z + l + u + v + w}{7} = 9 \implies x + y + z + l + u + v + w = 63 .... (2)\)

Putting (1) into (2), we have

\(18 + l + u + v + w = 63 \)

\(\therefore l + u + v + w = 63 - 18 = 45\)

Mean of l, u, v and w = \(\frac{45}{4} = 11.25\).

Explanation

(a)The following led to Naaman's healing:

(i) Naaman was a Syrian commander with leprosy. A little girl from the land of Israel who was living with Naaman's mistress told her about the prophet in Israel, who could cure Naaman of his leprosy. Naaman informed the king of Syrian, who gave him a letter to the king of Israel. He went to Israel with the letter and lots of expensive presents. He gave the letter to the king of Israel, who rent his clothes after reading and asked if he was God who could kill and keep alive. He became afraid, thinking that the king of Syria was looking for a way to attack him. Elisha, the man of God heard the news and sent for Naaman. As Naaman stepped at the door, Elisha sent his messenger to tell Naaman to go and wash himself seven times in River Jordan. At first, he hesitated, but was later persuaded by his servant to heed the instruction. He obeyed and went to River Jordan and dipped himself seven times in the river and was healed.

(ii) Naaman reaction to his healing was that he returned to the man of God and offered some gifts which were rejected.

(iii) The incident that followed this reaction was that he asked for Israelite soil to be taken to Syria for the worship of God. Gehazi, Elisha's servant went after Naaman and took some of the gifts which his master rejected. Elisha cursed him and he became a leper.

(b) The virtues and lessons that can be learnt from the entire episode are:

(i) God's blessings and healing are free of charge.

(ii) It pays to obey men of God and the fact that everyone is important in the society. The information that proved vital to Naaman came from a little maid.

(iii) God does not always work in the way man thinks. He works in mysterious way, that man can not comprehend. With God all things are possible. Everything obeys God's will. People should be humble in their dealings with fellow men. This is the only way to obey God's injunction on humility. God is the God of both the rich and the poor. There is no discrimination based on wealth or class. God sees everybody as equal for Him. It pays to be honest, for honesty is a virtue loved by God.

(a)The following led to Naaman's healing:

(i) Naaman was a Syrian commander with leprosy. A little girl from the land of Israel who was living with Naaman's mistress told her about the prophet in Israel, who could cure Naaman of his leprosy. Naaman informed the king of Syrian, who gave him a letter to the king of Israel. He went to Israel with the letter and lots of expensive presents. He gave the letter to the king of Israel, who rent his clothes after reading and asked if he was God who could kill and keep alive. He became afraid, thinking that the king of Syria was looking for a way to attack him. Elisha, the man of God heard the news and sent for Naaman. As Naaman stepped at the door, Elisha sent his messenger to tell Naaman to go and wash himself seven times in River Jordan. At first, he hesitated, but was later persuaded by his servant to heed the instruction. He obeyed and went to River Jordan and dipped himself seven times in the river and was healed.

(ii) Naaman reaction to his healing was that he returned to the man of God and offered some gifts which were rejected.

(iii) The incident that followed this reaction was that he asked for Israelite soil to be taken to Syria for the worship of God. Gehazi, Elisha's servant went after Naaman and took some of the gifts which his master rejected. Elisha cursed him and he became a leper.

(b) The virtues and lessons that can be learnt from the entire episode are:

(i) God's blessings and healing are free of charge.

(ii) It pays to obey men of God and the fact that everyone is important in the society. The information that proved vital to Naaman came from a little maid.

(iii) God does not always work in the way man thinks. He works in mysterious way, that man can not comprehend. With God all things are possible. Everything obeys God's will. People should be humble in their dealings with fellow men. This is the only way to obey God's injunction on humility. God is the God of both the rich and the poor. There is no discrimination based on wealth or class. God sees everybody as equal for Him. It pays to be honest, for honesty is a virtue loved by God.

Correct Answer: D)

NaClO

Correct Answer: B. a photon is emitted

Explanation

This is a typical scenario in atomic physics where an electron transitions from a higher energy level (orbit) to a lower energy level. During this transition, the electron loses energy, and this energy is emitted in the form of a photon. The energy of the emitted photon corresponds to the energy difference between the two energy levels, as described by the quantization of energy levels in the Bohr model of the atom.

Correct Answer: B) cocoa

Explanation

The cocoa swollen shoot virus disease (CSSVD) caused by the Cacao swollen shoot virus (CSSV) is one of the major disease problems affecting cocoa production in West Africa, most especially, Ghana, Cote D'Ivoire, Nigeria and Togo .

Explanation

(b) Characteristics of rain forest belt:

(i) It has tall trees with buttress roots evergreen and broad leaves.

(ii) Trees exist in different heights, storeys or layers, i.e. bottom, middle and upper layers.

(iii) Presence of little undergrowth due to canopy of the forest (iv) Presence of climbers, creepers, epiphytes and parasitic plants.

(v) It has numerous heterogeneous species of trees like lroko, Obeche, Mahogany and African walnut

(vi) Plant species are not in pure stand, i.e. trees are scattered.

(vii) Plants have soft and green barks.

(c) Ways in which the rain forest vegetation is important to the economy of Nigeria:

(i) Provision of tropical hardwood: It provides tropical hardwood like Iroko, Obeche and Mahogany timber for construction purposes.

(ii) Provision of employment: Lumbering of tress in this vegetation provides employment.

(iii) Farming activities: It gives rise to farming activities, especially the cultivation of tree crops in plantations, e.g. rubber, cocoa and oil palm.

(iv) Source of fuel: It is a source of fuel for cooking.

(v) Source of raw materials for industries: Rainforest has a lot of timber in which the industries use in their various activities, thereby generating revenue for the government.

(vi) Provision of food: It serves as source of food for people, and such food can be consumed locally and internationally.

(vii) Provision of medicine: Some plants in this belt have medicinal values to cure diseases

Correct Answer: A. number of neutrons

Correct Answer: D. Neither

Correct Answer: C. conducting trials and punishing persons involved in corruption matters

Correct Answer: A. ecology