RATIO AND PROPORTION
1.If a:b =5:9 and b:c=4:7 Find a:b:c?
Sol: a:b=5:9 and b:c=4:7=4*9/4:9*4/9=9:63/9
2.Find the fourth proportion to 4,9,12
Sol: d is the fourth proportion to a,b,c
3.Find third proportion to 16,36
Sol: if a:b=b:c then c is the third proportion to a,b
4.Find mean proportion between 0.08 and 0.18
Sol: mean proportion between a and b=square root of ab
mean proportion =square root of 0.08*0.18=0.12
5.If a:b=2:3 b:c=4:5, c:d=6:7 then a:b:c:d is
Sol: a:b=2:3 and b:c=4:5=4*3/4:5*3/4=3:15/4
6.2A=3B=4C then A:B:C?
Sol: let 2A=3B=4C=k then
A=k/2, B=k/3, C=k/4
7.15% of x=20% of y then x:y is
8.a/3=b/4=c/7 then (a+b+c)/c=
Sol: let a/3=b/4=c/7=k
9.Rs 3650 is divided among 4 engineers, 3 MBAâ€™s and 5 CAâ€™s such that 3 CAâ€™s get as much as 2 MBAâ€™s and 3 Engs as much as 2 CAâ€™s .Find the share of an MBA.
3C=2M, that is M=1.5C
3E=2C that is E=.66 C
M=1.5 and C=450.