JAMB Mathematics Past Questions & Answers - Page 246

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)

a²bx + ab²x; a²b - b²

abx(a + b); b(a² - b²)

b(a + b)(a + b)

∴ H.C.F. = (a + b)

$\frac{4\frac{3}{4} - 6\frac{1}{4}}{4\frac{1}{5} \text{ of } 1\frac{1}{4}}$

$\frac{19}{4}$ - $\frac{25}{4}$............(A)

$\frac{21}{5}$ x $\frac{5}{4}$.............(B)

Now work out the value of A and the value of B and then find the value $\frac{A}{B}$

A = $\frac{19}{4}$ - $\frac{25}{4}$

= $\frac{-6}{4}$

B = $\frac{21}{5}$ x $\frac{5}{4}$

= $\frac{105}{20}$

= $\frac{21}{4}$

But then $\frac{A}{B}$ = $\frac{-6}{4}$ $\div$ $\frac{21}{4}$

= $\frac{-6}{4}$ x $\frac{4}{21}$

= $\frac{-24}{84}$

= $\frac{-2}{7}$

Coca-cola = 10 bottles, Fanta = 8 bottles

Sprite = 6 bottles, Total = 24

P(cola-cola) = $\frac{10}{24}$

P(not coca-cola) = 1 - $\frac{10}{24}$

$\frac{24 - 10}{24}$ = $\frac{14}{24}$

= $\frac{7}{12}$

% of boxes containing at least 5 defective bolts each

= $\frac{7 + 17 + 10 + 8 + 6}{50}$

= $\frac{48}{50}$ x $\frac{100}{1}$

= 96%