Correct Answer: D. \(\frac{2}{15}\)

Correct Answer: B. age

Explanation

The age of the potential policy holder will determine the premium that would be required to be paid. For instance, a young agile person would be charged a different premium from a weak and aged person because the risk factor is different

Correct Answer: D. 0.3cm

Explanation

Y = 0.3 sin(0.5x - 50t) compare with,

y = A sin(kx - wt)

A = 0.3m

Correct Answer: C) from chains which bind rubber molecules together

Correct Answer: B. predict

Correct Answer: B. 22\(cm^{2}s^{-1}\)

Explanation

With radius = 7cm, \(Area = \pi r^{2} = \frac{22}{7} \times 7^{2}\)

= \(154cm^{2}\)

The next second, radius = 7.5cm, \(Area = \pi r^{2} = \frac{22}{7} \times 7.5^{2}\)

= \(176cm^{2}\)

Change in area = \((176 - 154)cm^{2} = 22cm^{2}\)

\(\therefore\) The rate of increase = \(22cm^{2}s^{-1}\)

OR

\(Area (A) = \pi r^{2} \implies \frac{\mathrm d A}{\mathrm d r} = 2\pi r\)

Given \(\frac{\mathrm d r}{\mathrm d t} = 0.5\)

\(\frac{\mathrm d A}{\mathrm d r} \times \frac{\mathrm d r}{\mathrm d t} = \frac{\mathrm d A}{\mathrm d t}\)

\(\frac{\mathrm d A}{\mathrm d t} = 2\pi r \times 0.5 = 2 \times \frac{22}{7} \times 7 \times 0.5\)

= \(22cm^{2}s^{-1}\)

Explanation

(a)(i)Population: This is a group of individuals; of the same species; inhabiting a particular area/habitat; at a particular point in time.

(ii)Competition: - This is the interaction between members of the same population/ species/intra - specific/two or more populations/species/inter - specific; occupying the same trophic level; to obtain mutually needed resources; that are short in supply in their environment.

(iii)Succession: - This is the step by step/orderly; and gradual replacement of communities; arising from a change in the environment/environmental factors; which leads to a climax/stable community.

(b) (i) Sources of noise pollution: -

• Electronic sound system
• Sirens
• Generators
• Airplanes
• Factory machines
• Industrial machines
• Canons shots/guns firing
• Artillery firing
• Quarry activity/construction site
• Motor vehicles.

(ii) Prevention:

• Legislation
• Education/public enlightenment
• Siting factories, industries, military site away from residential areas
• Use of sound proof/silent generators.

(c)(i) Effects of smoke on humans: -

• Causes breathing difficulties.
• Causes injury to the lining of respiratory tracts/ lungs.
• Reduces visibility; reduces photosynthesis leading to lower crop yield.
• Causes discomfort to the eyes.
• Contains carbon monoxide which is injurious to man.

(ii) Effects of sewage on human:

1. Untreated sewage discharged into water bodies makes water unfit for drinking/swimming
2. may cause spread of water borne diseases/correctly named borne disease.
3. its toxic to aquatic organisms thereby depleting food source for man.
4. makes water unsafe for domestic use.
5. leads to offensive odour.
6. poisonous substances may enter the food chain which is unsafe for man.

Correct Answer: C. self service

Explanation

self service is the system whereby customers select goods for themselves and pay at a checkout.

Correct Answer: A. Juz

Correct Answer: A. She marries Sebastian