Compounded Ratio: The compounded ratio of the ratios (a:b), (c:d) and (e:f) is (ace:bdf).
Duplicate Ratio: The duplicate ratio of (a:b) is (a2:b2)
Sub-Duplicate Ratio: The sub-duplicate ratio of (a: b) is (√(a ): √(b ) )
Triplicate Ratio: The Triplicate ratio of (a:b) is (a3:b3)
Sub-Triplicate Ratio: The sub-triplicate ratio of (a: b) is (a(1/3) ∶ b(1/3))
Componendo: If a/b=c/d then, the componendo is (a+b)/b=(c+d)/d.
Dividendo: If a/b=c/d then, the dividendo is (a-b)/b=(c-d)/d.
Componendo - Dividendo: If a/b=c/d then, the componendo - dividendo is (a+b)/(a-b)=(c+d)/(c-d).
EXERCISE:
Find out:
the fourth proportional to 4, 9, 12;
the third proportional to 16 and 36;
the mean proportional between 0.08 and 0.18
If x:y=3:4, find (4x+5y):(5x-2y)
Divide Rs. 1162 among A, B, C in the ratio 35:28:20
A bag contains 50p, 25p and 10p coins in the ratio 5:9:4, amounting to Rs.206. Find the no. of coins of each type.
If 1/5:1/x=1/x:1/125 , then the value of x is:
15
20
25
35
If x:y=5:2 then (8x+9y):(8x+2y)
22:29
26:61
29:22
61:26
Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is:
2:5
3:5
4:5
6:7
The ratio of the number of boys and girls in a college is 7:8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
8:9
17:18
21:22
cannot be determined
What is the ratio whose terms differ by 40 and the measure of which is 2/7?
