The volume of a cylinder whose height is 4cm and whose radius 5cm is equal to (π = 3.14)
3.13cm2
145cm2
314cm2
214cm2
Correct answer is C
“Explanation
V = πr2h
V = ?, h = 4cm, r = 5cm
V = 3.14(5)2 (4)
V = 3.14(25)(4)
V = 3.14 × 1200
= 314cm2
x = 2 or 1
x = 3 or -1
x = 1 or 0
x = 1 or 2
Correct answer is B
x2 − 2x − 3 = 0
−3x + x = − 2x
− 3x × x = − 3x2
(x2 − 3x)(x − 3) = 0
(x − 3)(x + 1) = 0
Either (x − 3) = 0 or (x + 1) = 0
x = 3 or − 1
Find the value of x if \( [ 1 ÷ 64^{(x + 2)}]= [4^{(x − 3)} ÷ 16^x ] \)
\( \frac{3}{2} \)
\( \frac{2}{3} \)
\( \frac{1}{3} \)
\( -\frac{3}{2} \)
Correct answer is D
\( [ 1 ÷ 64^{(x + 2)}]= [4^{(x − 3)} ÷ 16^x ] \)
\( 64^{−(x + 2)} = [4^{(x − 3)}] ÷[16^x] \)
breakdown 4,16,64 into a small index no
\( 2^{−6(x + 2)} = 2^{2(x − 3)} ÷ 2^{4(x)} \)
\( 2^{−6x− 12} = 2^{2x − 4x − 6} \)
\( 2^{−6x −12} = 2^{−2x − 6} \)
− 6x − 12 = − 2x − 6
Collect the like term
−6x + 2x = −6 + 12
−4x =6
x = \( \frac{6}{4} \)
x = \( \frac{−3}{2} \)
A man sells his new brand car for N420,000 at a gain of 15%. What did it cost him?
N410,000
N365, 217
N157, 250
N257,000
Correct answer is B
Cost Price:
Selling price = 100 : (100 + 15)
= 100 : 115
Cost Price
= 100 ÷ 115 of selling price (i.e N420,000)
= 100 ÷ 115 × N420,000
= N365,217.4
∴ Cost Price = N365, 217
5
3
6
1
Correct answer is C
132x = 708
\( 1 × x^2 + 3 × x^1 + 2 × x^0 \)
\( 7 × 8^1 + 0 × 8^0 \)
\( x^2 + 3x + 2 − 56 = 0 \)
\( x^2 + 3x − 54 = 0 \)
x(x + 9)−6(x + 9) = 0
(x + 9)(x − 6) = 0
Either (x + 9) = 0 or (x − 6) = 0
x = − 9 or +6
The positive values for x = 6
The base number for 132x = 1326