JAMB Mathematics Past Questions & Answers - Page 374

1,866.

Compute 110011₂ + 11111₂

1001010₂

1010010₂

1000110₂

1000100₂

View answer & explanation

Correct answer is B

110011₂ + 11111₂ = 1010010₂

1,867.

Evaluate \(\frac{2}{6-5\sqrt{3}}\)

\(-\left(\frac{12}{39}-\frac{10\sqrt{3}}{39}\right)\)

\(\frac{12}{39}-\frac{10\sqrt{3}}{39}\)

\(-\left(\frac{12}{39}+\frac{10\sqrt{3}}{39}\right)\)

\(\frac{12}{39}+\frac{10\sqrt{3}}{39}\)

View answer & explanation

Correct answer is A

\(\frac{2}{6-5\sqrt{3}} = \frac{2}{6-5\sqrt{3}} \times \frac{6+5\sqrt{3}}{6+5\sqrt{3}}\\
=\frac{2(6+5\sqrt{3})}{(6-5\sqrt{3})(6+5\sqrt{3})}\\
=\frac{12+10-\sqrt{3}}{36-25(3)}\\
=\frac{12+10-\sqrt{3}}{36-75}\\
=\frac{12+10-\sqrt{3}}{-39}\\
=-\left(\frac{12}{39}-\frac{10\sqrt{3}}{39}\right)\)

1,868.

Find the tax on an income of N20,000 if no tax is paid on the first N10,000 and tax is paid at N50 in N1000 on the next N5000 and at N55 in N1000 on the remainder

N500

N552

N255

N525

View answer & explanation

Correct answer is D

N20,000 - N10,000 = N10,000
1^st tax on N5000 at N50 per N1000
= 5*50 = N250
2^nd tax on the remaining N5000 at N55 per N1000 = 5*55 = N275
Total tax paid = N250 + N275
= N525