(b) In a school of 75 pupils, 42% of the pupils take Biology but= not Chemistry, 32% take both subjects and 10% of them take Chemistry but not Biology. How many pupils do not take either Biology or Chemistry? (6 marks)
6. (a) Juma bought motor vehicle spare parts from Japan worth 5,900,000 Japanese Yen. When he arrived in Tanzania he was charged custom duty of 25% on the spare parts. If the exchange rates were as follows:
(b) The distance of the horizon d km varies as the square root of the height h m of the observer above sea level. An observer at a height of 100m above sea level sees the horizon at a distance of 35.7 km.
(i) the distance of the horizon from an observer 70m above sea level.
Answer four (4) questions from this section. Extra questions will not be marked.
11. (a) Maximize f = 2y — x subject to the following constraints:
x ≥ 0
y ≥ 0
2x+y ≤ 6
x+2y ≤ 6
(b) Sara had 300 shillings to buy erasers and pencils. An eraser cost 20 shillings while a pencil costs 30 shillings. If the number of erasers bought is at least twice the number of pencils, formulate the inequalities that represent this information. (10 marks)
13. (a) Below is a circle with centre 0 and radius r units. By considering the circumference of the circle, the area of the circle, the given angle 0 and the degree measures of a circle (3600), develop the formula for finding: