好急o既問題>_<

memk

做做下數唔記得左ratio果d數.....
1) If 1/p : 1/q = 2:3 and q : r = 1:3,find p:q:r
ANS: 3:2:6

2)Amy and Billy shared some stamps in the ratio 3:5.If they shared the stamps in the ratio 5:7,Amy would receive 9 more stamps.Find the total number of stamps.
ANS:216

唔記得左點計呀.....唔該幫幫手>_<

卓霖

b)  forget, sor...maybe  too tired
a) = 1/p : 1/q = 2:3 等於交叉相乘q/p= 2/3,q/r=1/3 ...
q:p   = 2:3
q:   r=  1    : 3
-------------------
q:p:r = 2:3:6 ....p:q:r = 3:2:6