NECO MATHS THEORY PLS TAKE NOTE: ^ means Raise to power ============= root means square root sign ie _/ ============= As a maths student u knw wat base means eg: 244basen means 244n. ============ degree is a degree sign that looks like zero on top. =========== * means multiplication ============ ++++++++++++++++++++++++++ (1) (a) peugeout sector= 180/480*(360) =135 degree datsun sector= 108/480*(360) ford sector= 72/480*360 =54 degree toyota sector= 56/480*(360) =48 degree (1b) Pr(toyota)= 42/480 Pr(volkswagen)= 48/480 Pr(toyota or volkswagen)= (42/480)+ 48/480 =90/480= 9/48 =3/16 =========================== (3a) 13/4 +X/Y = 4/3 X/Y=4/5-13/16 X/Y=64-65/(16)(5) X/Y= -1/80 X:Y = -1:80 (3b) cost each machines = 25,000/12 = 2083.3naira. (i) cost of machines = 2083.3 *10 =20833.30 (ii) number of such machines = 175,000/2083.3 =84 machines ============================== (4) (i) draw a venn diagram U = universal set =40 mangoes (M) = 15 Pineapples(P)= 21 (ii) let X reps the no. that do not like mangoes and pineapples (ii) 9+6+15+X = 40 30+X =40 X = 40-30 X =10 (iii) . % of class of mangoes only = 9/40 * 100 = 22.5% =============================== (5) (a)244basen=1022base4 2*n^2+4*n^1+4*n^0=1*4^3+0+4^2+2*4^1+2*4^0 2n^2+4n+4=64+0+8+2 2n^2+4n+4=74 2n^2+4n+4-74=0 2n^2+4n-70=0 n^2+2n-35=0 n^2-5n+7n-35=0 n(n-5)+7(n-5)=0 n+7=0 or n-5=0 n=-7 or n=5 (b)Using similar triangle AZ/XZ=KZ/YZ 8/XZ=11/24 XZ=(8*24)/11 =17.45cm ============================= (9) Total surface area(A)=88cmΛ2 Height (H)=7cm (i)A=2*pie*r*h+2*pie*rΛ2 A=2*pie*r(h+r) 88=2*22/7*r(7+r) 88=6.29*r(7+r) 7r+rΛ2=88/6.29 7r+rΛ2=14 rΛ2+7r-14=0 using almighty formular r=-7+_root(7Λ2-4*1*-14)/2 r=-7+_root(49+56)/2 =-7+_root(105)/2 =-7+_10.25/2 r=-7-10.2/2 or-7+10.25/2 r=-8.625 or 1.625 Diameter(d)=2r 2*1.625 =3.625 (ii)Volume of the solid(v) =pie*rΛ2*h =22/7*(1.625)Λ2*7 =406.66/7 =58.09cmΛ3 (9b)
Posted on: Mon, 07 Jul 2014 12:06:54 +0000
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