The ratio of 4 litres to 900 mL is

1. 4 : 9
2. 40 : 9
3. 9 : 40
4. 20 : 9

When the number 210 is increased in the ratio 5 : 7, the new number is

1. 150
2. 180
3. 294
4. 420

The ratio of number of edges of a cube to the number of its faces is

1. 2 : 1
2. 1 : 2
3. 3 : 8
4. 8 : 3

If x, 12, 8 and 32 are in proportion, then the value of x is

1. 6
2. 4
3. 3
4. 2