Simplify and express in standard form \(\frac{0.00275 \times 0.00640}{0.025 \times 0.08}\)
8.8 x 10-1
8.8 x 10-2
8.8 x 10-3
8.8 x 103
Correct answer is C
\(\frac{0.00275 \times 0.0064}{0.025 \times 0.08}\)
Removing the decimals = \(\frac{275 \times 64}{2500 \times 800}\)
= \(\frac{88}{10^4}\)
88 x 10-4 = 88 x 10-1 x 10-4
= 8.8 x 10-3
At what rate would a sum of N100.00 deposited for 5 years raise an interest of N7.50?
\(\frac{1}{2}\)%
2\(\frac{1}{2}\)%
1.5%
25%
Correct answer is C
Interest I = \(\frac{PRT}{100}\)
∴ R = \(\frac{100 \times 1}{100 \times 5}\)
= \(\frac{100 \times 7.50}{500 \times 5}\)
= \(\frac{750}{500}\)
= \(\frac{3}{2}\)
= 1.5%
Correct 241.34(3 x 10\(^{-3}\))\(^2\) to 4 significant figures
0.0014
0.001448
0.0022
0.002172
Correct answer is D
first work out the expression and then correct the answer to 4 s.f = 241.34..............(A)
(3 x 10-\(^3\))\(^2\)............(B)
= 3\(^2\)x\(^2\)
= \(\frac{1}{10^3}\) x \(\frac{1}{10^3}\)
(Note that x\(^2\) = \(\frac{1}{x^3}\))
= 24.34 x 3\(^2\) x \(\frac{1}{10^6}\)
= \(\frac{2172.06}{10^6}\)
= 0.00217206
= 0.002172(4 s.f)
Find the derivative of the function y = 2x\(^2\)(2x - 1) at the point x = -1?
18
16
-4
-6
Correct answer is B
y = 2x\(^2\)(2x - 1)
y = 4x\(^3\) - 2x\(^2\)
dy/dx = 12x\(^2\) - 4x
at x = -1
dy/dx = 12(-1)\(^2\) - 4(-1)
= 12 + 4
= 16
\(\frac{-2}{7}\)
\(\frac{7}{6}\)
\(\frac{-6}{7}\)
2
Correct answer is D
Line: 2y+8x-17=0
recall y = mx + c
2y = -8x + 17
y = -4x + \(\frac{17}{2}\)
Slope m\(_1\) = 4
parallel lines: m\(_1\). m\(_2\) = -4
where Slope ( -4) = \(\frac{y_2 - y_1}{x_2 - x_1}\) at points (-1, -p) and (-2,2)
-4( \(x_2 - x_1\) ) = \(y_2 - y_1\)
-4 ( -2 - -1) = 2 - -p
p = 4 - 2 = 2