[" Life spam of tortoise is "^(*)],[bigcirc100Yrs],[" 0"200yrs],[" 0"300Yrs],[" O "400Yrs]

The half life period of four isotopes (i) 6.7 yr " " (ii) 8xx10^(3) yr (iii)5760 yr " " (iv) 2*35xx10^(5) yr, The most stable isotope is

The disintegration constant of radium with half-life 1600 yr is

A sum of money placed at compound interest doubles itself in 5 yr. In how many years, it would amount to eight times of itself at the same rate of interest? (A) 10 yr (B) 15 yr (C ) 7 yr (D) 20 yr

The ratio of the age of a father to that of his son is 5:2. If the product of their ages is 1000, then the father's age ( in yr) after 10 yr will be a

Harsha is 40 yr old and Rith is 60 yr old. How many years ago was the ratio of their ages 3 : 5 ? (A) 10 yr (B) 20 yr (C ) 37 yr (D) 5 yr