Question : On a shelf, books with white covers and those with orange covers are in the ratio 12 : 21. If there are 945 books with orange covers, then the number of books with white covers is:

Option 1: 645

Option 2: 540

Option 3: 1485

Option 4: 840

Question : The colour of the alluvial soil varies from _______.

Option 1: pale white to warm white

Option 2: light orange to dark orange

Option 3: orange to red

Option 4: light grey to ash grey

Question : A number is divided in the ratio 5 : 7. When 6 is added to each, the ratio changes to 7 : 9. Find the greater number.

Option 1: 12

Option 2: 18

Option 3: 15

Option 4: 21

Question : There is a ratio of 5 : 4 between the two numbers. If 40 percent of the first number is 12, then 50% of the second number is:

Option 1: 12

Option 2: 24

Option 3: 18

Option 4: 20

Question : A cyclist, after cycling a distance of 70 km on the second day, finds that the ratio of distance covered by him on the first two days is 4 : 5. If he travels a distance of 42 km on the third day, then the ratio of distance travelled on the third day and the first day is:

Option 1: 4 : 3

Option 2: 3 : 2

Option 3: 3 : 4

Option 4: 2 : 3

Question : If the ratio of areas of two circles is 4 : 9, then the ratio of their circumferences will be:

Option 1: 3 : 2

Option 2: 9 : 4

Option 3: 2 : 3

Option 4: 4 : 9