I solve it as the 280m train being stationary… and the 120m train moving at (42+30) = 72kph…. or 20mps
The front of the train will have to go 280m to pass the stationary train plus another 120m for the backs to clear… that is 400m in all.
The time to travel 400m at 20mps is 20secs
Answer:
Since the car has met the person 20 minutes before hand, it has actually saved 10 mins of journey (to and fro)
since the man has started 1.30 hrs before and car has met him 10 mins before actual time he takes to reach daily is 1hr and 20 mins
C
0987654321
(x**2 – 6* x + 5) = (x-1)*(x-5)
(x**2 + 2 * x + 1) = (x + 1) * (x+1) = (x+1)**2
For what x is (x-1)*(x-5)/( (x+1)**2) a minimum?
One way to answer this question is by using calculus.
Take the derivative, and set to zero.
Since this is a fraction of polynomials, and a fraction is
zero only if it’s numerator is zero, we need calculate only
the numerator of the derivative and set it to zero.
The numerator of the
Derivative of (x-1)*(x-5)/( (x+1)**2) is
( (x-1) + (x-5) ) ( x+1)**2 – (x-1)(x-5)( 2 (x+1) )
= (2 x – 6) (x+1)**2 – (2) (x-1)(x-5) (x+1)
= 0
Divide through by 2 (x+1)
(x-3)(x+1) – (x-1)(x-5) = 0
(x**2 – 2 x – 3 ) – (x**2 – 6 x + 5) = 0
x**2 – x**2 – 2 x + 6 x – 3 – 5 = 0
4 x – 8 = 0
x = 2
Plugging in x = 2 into the original
(x**2-6*x+5)/(x**2+2*x+1)
gives us (2**2 – 6 * 2 + 5)/(2**2 + 2*2 + 1)
= (4 – 12 + 5) / (4 + 4 + 1) = -3/9 = -1/3
Least value is -1/3
Average = (1+2+3+4+5+6+7+8+9)/3
= 45/3 = 15
Every side will contain sum of 15.
1st side contains 8 and 7.
2nd side contains 9 and 6.
3rd side contains 1,2,3,4 and 5.
(b) 330 is the amswer
as the no of toys are equall to no of students
18*18= 324
left out toys afetr distribution = 6
so 324+6= 330
x/2y=3/2…
therefore
2x=6y
x=3y
therefor
=21y+4y/3y-2y
=25y/y
=25..
there answer=25
so for the above question, we don’t have an option…so answer
is Data Insufficient..
41, 43, 47, 53, 61, 71, 73, 81
81
c=a/b
c=a-1
=>b=a/c
=>b=a/a-1
Since, there are 10 points on the circle and to draw a chord we need to connect any two points on the circle to make it a straight line, which implies that the number of chords = No of lines connecting any two points out of the 10 points
= 10C2 = 10*9/2 = 45 chords.
Robin =72
Dravid = 98
Azhar = 22
Sachine = 98
Total score = 290
( b ) 216.90
36,20
He will work for 35 days in 60 days to earn Rs.170 as per the condition
4/52 * 3/51