mathematics topics for competitive exams

 Q1If A is 28% more than B and C is 25% less than the sum of A and B, then by what percent will C be  more than A (correct to one decimal place)? (a) 32.2% (b) 28% (c) 43% (d) 33.6% 2) If the radius of a right circular cylinder is  decreased by 20% while its height is increased by  40%, then the percentage change in its volume  will be? (a) 1.04% increase (b)10.4% decrease (c) No increase or decrease  (d) 10.4% increase   3) Raghav spends 80% of his income. If his income  increases by 12% and the savings decrease by 10%,  then what will be the percentage increase in his  expenditure?   (a) 20.5 (b) 16 (c) 17.5 (d) 22

 Hello student , Good morning to all of you . I hope you are well and healthy  Today we read 20 most important Number system  question with best short trick . Let's Start.......💫💫⭐⭐ If you want to read in hindi translate this Page . Translation baar is given at right top corner .✅✅✅  Question:1⭐⭐⭐⭐⭐⭐⭐⭐⭐ Solve this  √3×√27= ? Answer: =√3×√27=√81=9 Note: you should  remember that 1. √a×√b = √ab⭐ 2.√(-a)×√b= -√ab=√a×√(-b) 3.√(-a) × √(-b)= -√ab  On this basics solve these type questions   Question 2. (√-3)×(√-27) =? Answer: Now we solve this question  =(√-3)×(√-27)= √(-3)×√(-3)×√(-3)×√(-3)= (-9) Very important question  Such type answer will be only use (-) sign    Divisibility rules