Let the number of males be given the name M.
Let the number of females be given the name F.
If 15 females are absent, then M will be twice that of
present females.
This means that M = 2 * (F – 15)
M = 2 * F – 30.
or 2 * F – M = 30.
Now if in addition to the 15 females being absent, we also
have 45 males being absent,
then this gives the equation,
(F – 15) = 5 * (M – 45)
which simplifies to
F – 15 = 5 * M – 225
5 * M – F = 210
Pulling the equations together, we get
5 * M – F = 210
-M + 2 * F = 30
Multiply the first equation by 2, and keep the second
equation as is.
10 * M – 2 * F = 420
– M + 2 * F = 30
Add the equations.
9 * M = 450
M = 50
Verify answer.
Calculate F
from – M + 2 * F = 30
-50 + 2 * F = 30
2 * F = 30 + 50
F = 40.
If 15 females are absent, then number of males will be twice
that of females.
40 – 15 = 25.
50 = 2 * 25. Confirmed.
If also 45 males were absent, then female strength would be
5 times that of males.
Female strength is 25 due to the 15 females being absent.
50 – 45 = 5.
25 = 5 * 5. Confirmed.
31
Speed of Stream = 1/2 (Downstream Speed – Upstream Speed)
=1/2(40-14)
=1/2(26)
=13km/h
method 2:
for down stream case :speed=Boat speed + Stream speed
for up stream case :speed=Boat speed – Stream speed
therefore, Bs + Ss =40
Bs – Ss =14
(-) (-) (-)
———————
2Ss=26
Ss=26/2 = 13Km/h
Stream speed= 13Km/hr
Statements :
No man is a donkey. Rajesh is a man.
Conclusions :
I. Rajesh is not a donkey.
II. All men are not Rajesh.
E
24*4= x(x+4)
solve this
answer is x=8
X+4= 12
P+C+M=80
P+C=70
Therefore M=10
Given , P+M=90
If M=10
P=80
@ Aprameya Shyam
length=x does not imply breadth=36-x
2x+4y=36.
3 possible answers are
(2,8) -> 16sqcm.
(4,7) -> 28sqcm.
(6,6) -> 36sqcm
16, 25, 36, 72, 144, 196, 225
72
Because it is not a square number
C
Example 1:
Assign, A=20, B=10, C=5, D=5(Because C is equal to D as
given), E=1.
A/B = 20/10 = 2. So A/B = 2
A/C = 20/5 = 4. So A/C = 4
A/E = 20/1 = 20. So A/E = 20
Therefore “A/E is Greatest”
Example 2:
Assign, A=100, B=50, C=20, D=20(Because C is equal to D as
given), E=10.
A/B = 100/50 = 2. So A/B = 2
A/C = 100/20 = 5. So A/C = 5
A/E = 100/10 = 10. So A/E = 10
Therefore “A/E is Greatest”
15,25
10000