If 1 apple is equal to 6 bananas, how many bananas will be equal to 12 apples?

Mani is double the age of Prabhu , Ramona is half the age of Prabhu . If Mani is sixty years old , find out the age a Ramona . 

If you write down all the numbers from 1 to 99, then how many times do you write 3?

If '+' becomes '-' and '×' becomes '÷', find the value of ((175 + 160) × 50) × 10.

The ratio of present ages of Suresh and Manish are 5 : 1 respectively. After how many years the ratio of the ages of Suresh and Manish will become 3 : 1 if the present age of Manish is 7 years -

The ratio of the present age of the two brothers is 1: 2. And 5 years ago this ratio was 1: 3. So what will be the ratio of their age after 5 years.

The weights of 4 boxes are 70, 100, 20 and 40 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes and in a combination a box can be used only once. 

The ratio of the number of girls to the number of boys in a town is 90 %. If the total number of boys and girls in the town is 190, how many girls are in the town?