JAMB Mathematics Past Questions & Answers - Page 70

347.

The table shown gives the marks scored by a group of student in a test. Use the table to answer the question given.

Mark 0 1 2 3 4 5
Frequency 1 2 7 5 4 3

 

What is the median mark?

A.

1

B.

2

C.

3

D.

4

Correct answer is C

Total frequency = 1 + 2 + 7 + 5 + 4 + 3 = 22

  Median is the middle number

 = \(\frac{Nth}{2}\)

  term = \(\frac{22th}{2}\) = 11th term

  Going in ascending order, 11th term is 3, going in descending order 11th term is 3

  Median = 3 + \(\frac{3}{2}\) = \(\frac{6}{2}\) = 3

  Answer is C

348.

If the simple interest on a sum of money invested at 3% per annum for 2\(\frac{1}{2}\)  years is N123, find the principal.

A.

N676.50

B.

N820

C.

N1,640

D.

N4,920

Correct answer is C

No explanation has been provided for this answer.

349.

Make T the subject of the relation.

A.

T = \(\frac{R + P3}{15Q}\)

B.

T = \(\frac{R - 15P^3}{Q}\)

C.

T =R - \(\frac{15P^3}{Q}\)

D.

T = \(\frac{15R + Q}{P^3}\)

Correct answer is C

P = (\(\frac{Q( R - T )}{ 15})^\frac{1}{3}\)

take cube of both sides

\(P^3 =\frac{Q( R - T)}{ 15}\)

cross multiply

\(15P^3 = Q( R - T)\)

\(\frac{15P^3}{Q}\) = R - T 

T = R - \(\frac{15P^3}{Q}\) 

350.

Simplify

\(\frac {25^{\frac{2}{3}} \div  25^{\frac{1}{6}}} {(\frac{1}{5})^{\frac{7}{6}} \div (\frac{1}{5})^{\frac{1}{6}}}\)

A.

25

B.

1

C.

\(\frac{1}{5}\)

D.

\(\frac{1}{25}\)

Correct answer is A

\(\frac {25^{\frac{2}{3}} \div  25^{\frac{1}{6}}} {(\frac{1}{5})^{\frac{7}{6}} \div (\frac{1}{5})^{\frac{1}{6}}}\)

= \(\frac{25^{\frac{2}{3} - \frac{1}{6}}}{(\frac{1}{5})^{\frac{7}{6} - \frac{1}{6}}}\)

= \(\frac{25^{\frac{1}{2}}}{(\frac{1}{5})}\)

= \(5 \div \frac{1}{5}\)

= 25