Q4 in AP,GP,HP. I have commented my answer. Please let me know if that's correct

Hi Pulkit, thanks for your comment. Let's continue the discussion on that same thread.

how do i solve percentage questions

Hi Udita, the best way to solve percentage questions is to reduce them to fractions and then form equations based on the conditions given. The equations thus formed are generally linear or quadratic and can be easily solved. Finally, convert the fractions into percentages to get the answer.

Remainder when 8^129 is divided by 131 ?

8 and 131 are co-prime and Euler's Totient of 131 is 130.=> $$8^{130}$$ mod 131 = 1=> (8 mod 131) * ($$8^{129}$$ mod 131) = 1 mod 131=> 8 * ($$8^{129}$$ mod 131) = 131k + 1If p is equal to $$8^{129}$$ mod 131, then=> 8p = 131k + 1This has a solution at k = 5. At k = 5, the value of p is 82. We know that p is equal to $$8^{129}$$ mod 131.Hence, $$8^{129}$$ mod 131 = 82

What will be the remainder when 36! is divided by 73 ?

By Wilson's theorem, 72! mod 73 = 7272 mod 73 = -171 mod 73 = -2 and so onSo, 72! mod 73 = $$36!^2$$ mod 73 = 72 => $$t^2$$ mod 73 = 72=> $$t^2$$ + 1 = 73kThis satisfied for t = 27So, 27 is the remainder of 36! mod 73

The death rate of a country fell from 45% to 20% in 30 years. What is the approximate fall in the death rate of the country per year in those 10 years?

This is the solution given by Cracku - is this correct? I don't understand how 1+30r is getting changed to 1+10r Let the rate of fall be rSo, 45(1+r) 30 = 20 => (1+r) 30 =0.44 Approximate the expression as 1+30r => 1+10r = 0.44 => r = -0.56/10 = -0.056 So, the rate of fall is 5.6%

how can i view my solutions of the dashcats ? unable to access them

Hi Nisha, the results and solutions for all Dashcats are up. Please let us know if there is still a problem.

How many values can natural number n take, if n! Is multiple or 7^6 but not of 7^9 ? approach plz

The number of 7s that 42! has is [$$\frac{42}{7}$$] = 6The number of 7s that 56! has is [$$\frac{56}{7}$$] + [$$\frac{56}{7^2}$$] = 9So, all the values from 42! to 55! are multiples of $$7^6$$

Best way to prepare Vocabulary for CAT Exams?

Hi Himanshu, a good way to prepare for Vocab is to try to find out the meanings of new words as you come across them during your preparation and to use those words in your day-to-day life. This will help you assimilate those words. It's a bad idea to try to learn words from Vocab lists by rote. Having said that, the concentration on Vocab in CAT has been decreasing in the last few years. There was no Vocab question in CAT 2015.