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
890.488
The numbers that lie between 100 and 1000 which are divisible by 14 are 112, 126,140 …,994
a = 112; l = 994, d = 14
n= (l−a)/d+1
= (994-112)/14+1
= 64
Sn=n/2(l+a)
= 64/2(994+112)
= 32*1106
= 35392
answer is 100
[(45 men*8hours)/30 meters]=12 (working rate)
[(x men*5 hours)/50 meters]=12 (working rate is same)
then x=100
Pen
32
Solution:
life as a boy = 1/4
life as a youth = 1/8
life as an active man = 1/2
sum of life as boy, youth and active man = 1/4 + 1/8 + 1/2 = 7/8
life as an old man = 1 − 7/8 = 1/8
1/8 Wrinkle’s life (as an old man) is 8 years.
and 1/2 = 1/8 *4
So, 1/2 Wrinkle’s Age (as active man) = 8*4 = 32years.
I think the answer is: 16
the woman faster *1.5 from the man, every day.
because that, the exersize is:
24/1+1.5+x=6
x=1.5
24/1.5=16!
Since the total train length passed the tunnel so the distance would be the length of train added to the tunnel legth
D=150+300=450 mt.
speed = distance/time
speed = 450/(40.5/3600)
speed =40,000 mt/sec
area is given by Area of Rectangle = Length of Rectangle*(sqrt((Diagonal of Rectangle^2)-(Length of Rectangle^2)))
so substituting we get area=4*(sqrt((25-16)))
area=4*(sqrt(9))
since area cannot be negative hence we take sqrt of 9 as 3 (as sqrt of 9 is 3 and -3 as well)
area=4*3=12m^2
(c) 25%
20*55*65=y*65*75
y=(20*55*65)/(65*75)
y=14.667 =15
y=15
% reduction=(20-15)/20=25%
(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
the pool will be half full at the 19th day .so that it doubles on the 20th day and becomes full
4500 sal of jan
b
600