The mean proportion between x and y is 6. The third proportional to x and y is 48. Then x : y equals :

1. 1 : 3

2. 1 : 4

3. 1 : 6

4. 1 : 9

When 30% of one number is subtracted from another number, the second number reduces to its four-fifths. What is the ratio of the first to the second number?

1. 2 : 5

2. 2 : 3

3. 4 : 7

4. cannot be determined

Five mangoes and four guavas cost as much as three mangoes and seven guavas. What is the ratio of the cost of one mango to the cost of one guava?

1. 1 : 3

2. 3 : 2

3. 4 : 3

4. 5 : 2