NECO Mathematics Past Questions & Answers - Page 22

106.

If the first term of an AP is 1.2 and the common difference is also 2, what is the mean of the first five terms?

A.

2

B.

4

C.

6

D.

8

E.

10

Correct answer is C

No explanation has been provided for this answer.

107.

Find the area of a triangle ABC such that a = 16cm, b = 14cm, c = 12cm, leave your answer in surd form

A.

5\(\sqrt{15}\)cm2

B.

7\(\sqrt{15}\)cm2

C.

21\(\sqrt{3}\)cm2

D.

21\(\sqrt{5}\)cm2

E.

21\(\sqrt{15}\)cm2

Correct answer is E

No explanation has been provided for this answer.

108.

Evaluate \(1011_{two}\) + \(1101_{two}\) + \(1001_{two}\) - \(111_{two}\)

A.

10001\(_{two}\)

B.

11001\(_{two}\)

C.

110001\(_{two}\)

D.

11010\(_{two}\)

E.

10001\(_{two}\)

Correct answer is D

Convert each value to decimal (base 10)

\(1011_{two}\) → 11

+ \(1101_{two}\) → 13

+ \(1001_{two}\) → 9

- \(111_{two}\) → 7

: 11 + 13 + 9 - 7 = 26

26 → \(11010_{two}\)

109.

Two similar cylindrical cans have heights of 7cm and 21cm, if the smaller holds 250g of sugar, how many kg of sugar will the larger one hold?

A.

0.75

B.

1.5

C.

2.25

D.

3.5

E.

6.75

Correct answer is E

- If two solids are similar, the ratio of their volumes is equal to the cube of the ratio of their corresponding sides.

Given: Heights of cylinder  -->     21 : 7 or  3 : 1 = \(\frac{3}{1}\) 

                                = 3 times height enlargement

            Volume / Capacity of larger cylinder = 3\(^3\) \(\times\) 250g 

                                = 27 \(\times\) 250g = 6,750 or 6.75kg

 

110.

If y varies inversely as x2, how does x vary with y?

A.

x varies inversely as y2

B.

x varies inversely as \(\sqrt{y}\)

C.

x varies directly as y2

D.

x varies directly as \(\sqrt{y}\)

E.

x varies directly as y

Correct answer is B

No explanation has been provided for this answer.