At some instant two radiioactive substances are having amount in the ration 2:1 . Their half lives are 12 hrs and 16hrs then after two days the ratio of their quantities is
1: 1
2:1
1:2
1:4

At any instant, the ratio of the amounts of two radioactive substance is 2:1 . If their half-lives be, respectively, 12h and 16h , then after two days, what will be the ratio of the substances?

Three samples of a radioactive substance have activity in a ratio 2 : 5 : 7 , then after two half lives the ratio of their activities will be:

Two spheres made of same substance have diameters in the ratio 1:2. their thermal capacities are in the ratio of

The number of nuclei of two radioactive substance is the same and their half-lives are 1 year and 2 years respectively. The ratio of their activities after 6 years will be

Two radioactive substances X and Y initially contain an equal number of atoms. Their half-lives are 1 hour and 2 hours respectively. Then the ratio of their rates of disintergration after two hours is

Two radioactive substances X and Y initially contain equal number of atoms. Their half-lives are 1 hour and 2 hours respectively. Calculate the ratio of their rates of disintegration after four hours.

A radioactive substance decays to 1//16^(th) of its initial mass in 40 days. The half life of the substance, in days, is :

Densities of two gases are in the ratio 1: 2 and their temperatures are in the ratio 2:1 , then the ratio of their respective pressure is

The ratio of the radii of two cylinder is 1:2 and the ratio of their heigths is 2:1. Find the ratio of their volumes.

The ratio of the radii of two cones is 1:2 and the ratio of their heigths is 2:1. Find the ratio of their volumes.