If you save 1 paise today, 2 paise next day and 3 paise succeeding day and so on, what will be your saving in 365 days ?

A sample of radioactive substance is found 90% of its initial amount after one day . What % of the original sample can be found after 3 days?

2 men and 7 boys can do a piece of work in 4 days. The same work is done in 3 days by 4 men and 4 boys. How long would it take one man and one boy alone to do it ?

I read 2/5 of the book inn one day and 1/5 of the book next day. What portion of book did I read in two days?

Find the probability of drawing one rupee coin from a purse with two compartments one of which contains 3 fifty paise coins and 2 one rupee coins and the other contains 2 fifty paise coins and 3 one rupee coins.

2 men and 5 boys can do a piece of work in 4 days, while 4 men and 4 boys can do it in 3 days. How long would it take one man alone to do it and how many days would it take one boy alone to do it ?

A JEE aspirant estimates that she will be successful with an 80 percent chance if she studies 10 hours per day, with a 60 percent chance if she studies 7 hours per day and with 40 percent chance if she studies 4 hours per day. She further believes that she will study 10 hours, 7 hours and 4 hours per day with probabilities 0.1, 0.2 and 0.7 respectively. Given that she will achieve success, the chance she studied for 4 hours is?