Ratio & Proportion, Alligation or Mixture

Jo's collection contains US, Indian and British stamps. If the ratio of US to Indian stamps 5 to 2 and the ratio of Indian to British stamps is 5 to 1, what is the ratio of US to stamps?

The average of two numbers is 62. If 2 is added to the smaller number, the ratio between the numbers becomes 1 : 2. What is the smaller number?

A sum of tk. 427 is to be divided among A, B and C such that 3 times A's share, 4 times B's share and 7 times C's share are all equal. The share of C is:  

The ages of Sabiha and Suriya are in the ratio of 7 : 3 respectively. After 6 years, the ratio of their ages will be 5 : 3. What is the difference in their ages?

A mixture of 20kg of spirit and water contains 10% water. How much water must be added to this mixture to raise the percentage of water to 25%?

If A : B = 5 : 4 and A : C = 6 : 5 then, C : B = ?

In a club 50% of the male voters and 80% of the female voters voted for candidate A. If candidate A received 70% of the total votes, what is the ratio of male to female voters?

A milkman pays Tk. 6.40 per liter of milk. He adds water and sells the mixture at Tk. 8 per liter. By doing this, he makes 37.5% profit. Find the proportion of water to milk received by the customer.

How many litres of a 90% of concentrated acid needs to be mixed with a 75%. Solution of concentrated acid to get a 30 liter solution of 78% concentrated acid?

A jar contains white, red and green marbles in the ratios 2 : 3 : 5. Six more green marbles are added to the jars, and then the ratio becomes 2 : 3 : 7. How many white marbles are three in the jar?

The ages of A and B are in the ratio 6 : 5 and the sum of their ages is 44 years. What will be the ratio of their ages after 8 years?

The ratio of two numbers is 2 : 3. The sum of the numbers is 100. The difference between the two numbers is:

If A and B are in the ratio 3 : 4, and B and C in the ratio 12 : 13, then A and C will be in the ratio

The present ratio of students to teachers at a certain school is 30 to 1. If the student enrollment were to increase by 50 students and the number of teachers were to increase by 5, the ratio of students to teachers would then be 25 to 1. What is the present number of teachers?

A mixture of 72 kg contains 17 parts A, 3 Parts of B, 4 parts of C. Find the quantity of B?

For many two numbers m, n ; (m + n) : (m - n) : mn = 7 : 1 : 60. Find the value of 1/m : 1/n 

The ratios of incomes of A and B is 5:4 and the ratio of their expenditures is 3:2. If at the end of the year each save tk 1600,then the income of A is:

In a class, the ratio of the number of boys to girls is 6 : 3. What percent of the members of the club are girls?

125 gallons of a mixture contains 20% water. What amount of additional water should be added such that water content be raised to 25%?

A dog takes 3 leaps for every 5 leaps of a hare. If one leap of a dog is equal to 3 leap of the hare then find the ratio of the speed of the dog to that of the hare is :