1991 - JAMB Mathematics Past Questions and Answers - page 1

PQM = 110o(Ext. < of a cyclic quad)
MPQ = 180o - (110 + 55)
= 180o - 165o
= 15o
Users' Answers & Comments
ADB = 180o - 152o = 28o
28o + y + 30o = 180o
y = 180o - 58o
= 122o
Users' Answers & Comments
Since PQRS is quadrilateral 2y + 2x = QPS = 360o
i.e. 2(y + x) + QPS = 360o
QPS = 360o - 2(y + x)
But x + y + 68o = 180o
x + y = 180o - 68o = 180o
x + y = 180o - 68o
= 112o
QPS = 360o - 2(112o)
360o - 224o = 136o
Users' Answers & Comments

3 - (\frac{1}{3}) - ((\frac{5}{4}) x (\frac{2}{3})) + 1(\frac{2}{5})
= (\frac{10}{3}) - (\frac{5}{6}) + (\frac{7}{5})
= (\frac{100 - 25 + 42}{30})
= (\frac{117}{30})
= 3.9
(\approx) 4
Users' Answers & Comments(\begin{array}{c|c} 7056 \ \text{- 4577} \hline 2257 \end{array})
By trial and error method
Let the base to 8
i.e. Let n = 8 and it is easily verified that the subtraction holds.
The subtraction does not hold when other values of n are tried
n = 8
Users' Answers & Comments((\frac{1}{0.05}) + (\frac{1}{5.005})) - (0.05 x 2.05)
((\frac{1}{0.05}) x 5.005) - (0.05 x 2.05)
(\frac{500.5}{0.05}) - 1025
100.1 - 0.1025
= 99.9975
99.998 to 3 sig. fiq.
Users' Answers & CommentsP produces 20,000 bags
P reduces production by 5%
i.e. reduction = (\frac{5}{100}) x (\frac{20000}{1})
= 1000
Q produces 15000 bags
Q increases production by 5%
i.e. increase = (\frac{5}{100}) x (\frac{15000}{1})
= 750
Effective loss by the two = 1000 - 750
= 250 bags
Users' Answers & Comments