15 litre water contains 20% alcohal ie. 12 (water)+ 3
(alcohol).
after adding 5 liter water it becomes 12+5=17 (water)& 3
(alc.).
ie. 17:3 and answer will be 85:15. ie. 15%.
I agree with @TUMWINE PETER
10%
Let three consecutive even numbers be 2n,2n+2,2n+4
product=2n(2n+2)(2n+4)
If n=1,
product =2(4)(6)=48.
So, all the numbers will be divisible by 48 if change n.
Very great things your doing
Fathers before age=3*before sons age—-(1)
After 2.5 years..
Fathers before age+2.5 years =2.5*sons age—-(2)
Substitute (1) in (2),
3*sons before age+2.5 years=2.5*sons age
0.5*sons age=2.5 years
Sons before age=5years
So current age after 2.5 years,
Sons before age+2.5 =5+2.5=7.5 years
6/11 or 54.54%
(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
Let the person ate x banana on first day, so below is the equation for five days
X+x+6+x+12+x+18+x+24=100
So, he ate 8 banana first day
suppose
pipe:
A -30 hours A’s effeciency (60/30) =2
60( lcm of 30 and 20)
B- 20 hours B’s effeciency (60/20)=3
time taken by both to fill = 60/5 =12 as given in question (effeciencies of both a+b =2+3=5)
time taken by faster pipe i.e b = 60/3 =20
79.2
2.88
9 and 16
let x be sum.
SI of 18% for 1 year= x*18/100=0.18x;
SI of 18% for 2 years is 0.36x;
SI of 12% for 1 year= x*12/100=0.12x;
SI of 12% for 2 years is 0.24x;
Given, 0.36x-0.24x=840
0.12x=840
x=840/0.12=7000.
4%
24*4= x(x+4)
solve this
answer is x=8
X+4= 12
3600