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s radius. When the mass of the ball is 500 g and the radius is 5 cm, its density is 2 g
Calculate radius of a solid spherical ball of mass 540 g and density of 10 g per em”. E
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11. Three quantities 1, 2 and y are such that t varies directly as x and inversely as the square
root of y. Find the percentage decrease in t if x decreases by 4% when y increases by
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..Given that y is inversely proportional to x" and k as the constant of proportionality;
(a) () Write down a formula connecting y, x, n and k.
(i) If r= 2 when y = 12 and x = 4 when y = 3, write down two expressions for k in
terms of n. Hence, find the value of n and k.
(b) Using the value of n obtained in (a) (ii) above, find y when x=5
3
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13. Three variables p, q and r are such that p varies directly as q and inversely as the squa
(a) When p=9,9 = 12 and r= 2. Find p when q = 15 and r= 5
(b) Express q in terms of p and r.
(c) If p in increased by 20% and r is decreased by 10%, find:
(i) a simplified expression for the change in q in terms of p and r.
(ii) the
centage change in q.