Could anyone explain to me how do we arrive at the surjection formula of
m^n-mc1(m-1)^n+mc2(m-2)^n-mc3(m-3)^n ?
In a triangle XYZ r in the inradius ,R is the circum radius and A is the area of triangle,if h1,h2,h3 are altitudes of triangle then 1/h1 + 1/h2 + 1/h3 ?
a)r/A
b)1/R
c)1/r
d)R/A
e)r*A
plz ansr this
two guys A and B are walking down an escalator in the direction of motion of escalator A takes 2 steps on the same time B takes 1 step,When A takes 60 steps he gets out of the escalator while B takes 40 steps to get out of escalator.Find the number of steps in the escalator when it is stationary?
a)80
b)90
c)120
d)150
e)100
if x, y , z are positive integers such that (x^2+4xy+4y^2+2z^2) is minimum and xyz=32 then what is the value of x+y+z=?
help m wit this
q2
N is a set of natural number less than 100 which can written of sum of two or more consecutive natural numbers . Find maximum possible number of elements possible in N?
Remainder (21^231)/25? Approach ?
A square is inscribed in a semi circle of radius 10 cm. What is d area of d square inscribed given a side of the square is along d diametr of the semicircle?
Explanations will be really appreciable!
last two digits of 148^1024
A tank is fitted with a pipe which fills it at 10 litres/hrs. After 4hours, a leak develops in in tank. If the leak had developed after 3 hrs instead of 4,it would have taken 2 hours longer to fill the tank. How much it take to fill the tank of 100l capacity if leak existed from he beginning
Share the approach please
- 20
- 30
- 15
- 25
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There are 51 senators in a senate. The senate needs to be divided into n committees such that each senator is on exactly one committee. Each senator hates exactly three other senators. (If senator A hates senator B, then senator B does 'not' necessarily hate senator A.) Find the smallest n such that it is always possible to arrange the committees so that no senator hates another senator on his or her committee.
P.S. Don't have OA.
Yamini and Zora are standing 25 km apart. Zora starts moving towards Yamini. After 40 minutes Yamini also starts moving towards Zora. By the time Yamini covers 5 km, Zora has covered 15 km. They meet at a point 7 km from the starting point of Yamini. What is the speed of Yamini?
Let f(x) be a function such that f(x-1) + f(x+1)=rt(2)*f(x). Then for what value of y is the relation f(x+y)=f(x) necessarily true for every real x?
1) 4
2) 6
4) 12
This is a simple question, but for some reason troubling me.
Mohit and Saket started a business with equal aggregate investments. Mohit made one time investment in the beginning while Saket kept on investing equal monthly amount till the 8th month from the starting. If the total profit made in the business at the end of the year was 16400, find the share of Mohit.
Please give a solution to above problem along with explanation.
Thanks in advance 😉
Q1. In how many ways a selection can be made of atleast one fruit out of 5 bananas, 4 mangoes and 4 almonds?
a) 129 b) 149 c) 139 d) 109
Q2. There are 5 different Jeffrey archer books, 3 different sidney sheldon books and 6 different john grisham books. The number of ways in which at least one book can be given away is :
a) (2^10)- 1 b) (2^11)-1 c) (2^12)-1 d) (2^14) -1
Please share the approach for both these questions...i find them ssooooo confusing! 
In a certain game, the only points one can score is either 7or 9. What is the highest number one cannot obtain in this game?
In ΔABC, D and E are two points on the side BC such that BD = DE = EC and AB = AC. If angle(DAE) = angle(ABC) and the area of the ΔABC is (3√7)/4 cm2, what is the length (in cm) of side AC?
A box contains 20 red balls, 25 blue balls, 30 green balls and 32 black balls. What is the minimum number of balls that one has to draw from the box in order to be sure of having at least one ball of each of the four colours?