2007 - WAEC Mathematics Past Questions and Answers - page 5
Sum = 8 + 6 + 7 + 2 + 0 + 4 + 7 + 2 + 3 = 39
mean = (\frac{39}{9}) = 4.33
then (\frac{sum}{mean}) = (\frac{39}{4.33})
= 9
cos 40 = (\frac{x}{200})
x - 200 x cosx
= 200 x 0.7660
x = 153.2m
Find the value of a if log10 a + log10a2 = 0.9030
Log a + log a2 = 0.9030
log (a x a2) = 0.9030
log a3 = 0.9030
a3 = 10^.9030(antilogarithm table)
a3 = 7.998
a = 3\(\sqrt{7.998}\)
a = 1.6
Let normal working hour = x
let overtime = y
after 10 hours = N31.00
1 x 2.50x + 4y = 31
4 x x + y = 10
2.50x + 4y = 31
- 4x + 4y = 30
----------------
-1.5x = -9
x = 6; x + y = 10
6 + y = 10
y = 10 - 4
y = 4hrs for over time
SI = (\frac{PRT}{100})
39 = (\frac{520 \times R \times 3}{100})
1560R = 3900
R = (\frac{3900}{1560})
= 2.5%
R = 2(\frac{1}{2})%
By Pythagoras theorem
h2 = (2(\sqrt{3})^2 - (\sqrt{3})^2)
= 22((\sqrt{3})^2 - 3)
4(3) - 3 = 112 - 3
h2 = 9
h = (\sqrt{9})
= 3cm
2 - x - x2; (2 - 2x) + (x - x2)
= 2(1 - x) + x(1 - x)
= (1 - x)(2 + x)
= 1 - x
(\frac{a + bc}{wd + f}) = g(cross multiply)
a = bc + wdg + fg
wdg = a + bc - fg
w = (\frac{a + bc - fg}{dg})
4x - 3(2x - 1) > 1
4x - 6x + 3 > 1
-2x > 1 - 3; 2x > -2
x < (\frac{-2}{-2})
= x < 1