1990 - WAEC Mathematics Past Questions and Answers - page 1

125\(^{\frac{-1}{3}}\) x 49\(^{\frac{-1}{2}}\) x 10\(^0\)

= 5\(^{-1}\) x 7\(^{-1}\) x 1

= \(\frac{1}{35}\)

3\(^{2x}\) = 27

3\(^{2x}\) = 3\(^3\)

2x = 3

x = 1.5

0.00562 = 5.62 x 10\(^{-3}\)

\(\frac{\log \sqrt{8}}{\log 8}\)

= \(\frac{\log 8^{\frac{1}{2}}}{log 8}\)

= \(\frac{\frac{1}{2} \log 8}{\log 8}\)

= \(\frac{1}{2}\) 

log x = \(\bar{2}.3675\) ; log y = 0.9750

\(x = 10^{\bar{2}.3675} = 0.02331 \)

\(y = 10^{0.9750} = 9.441 \)

\(x + y = 9.4641 \approxeq 9.46\)

%error = \(\frac{1.21 - 1.12}{1.21} \times 100%\)

= \(\frac{9}{121} \times 100%\)

= 7.44%

\(U_{n} = a + (n - 1)d\)

\(U_{4} = 2 + (4 - 1) \times 0.5\)

= \(2 + 1.5\)

= 3.5