I WANT THEIR ANS AND SHOW THE WORKING STEP PLZ~
1. if z varies directly as y^2 and inversely as x. which of the following must be
constant?
A. xy^2z
B. y^2z / x
C. xz / y^2
D. z / xy^2
2. it is given that x varies directly as y and inversely as z^2. if y is decreased by
10% and z is increased by 20%, then x is decreased by ?%.
3. it is given that y is partly constant and partly varies directly as x. when x=2,
y=17 and when x=4,y=11. find x when y=5.
4. if 1/a : 1/b = 2:3 and a:c = 4:1, then a:b:c = ? : ? : ?
5. if a:b =2:3, a:c = 3:4 and a:d = 4:5, then b:c:d = ?:?:?
6. if (x+2y)/(3x-4y) = 5, then x:y=?:?
7. if x:y =3:4 and 2x+5y=598,find x.
8. if 1 australian dollar is equivalent to 4.96 HKD and 100 japanese yen are
equivalent to 5.33 HKD, how many japanese yen are equivalent to 1 australian
dollar?
9. if 9a^2 - b^2 and ab < 0, then a-b / a+b =?
10. tea A and tea B are mixed in the ratio x:y by weight. A costs $80/kg and B
costs $100/kg. if the cost of A is increased by 10% and that of B is decreased by
12%, the cost of mixture per kg remains unchanged. find x:y.