TOTAL NUMBER OF BOOKS 40+40=80
ISSUED BOOKS 30
REMAINING BOOKS 80-30=50
RATE=50/80=5/8
Day = Night
White = Black
A=P+SI——(1)
sum of money after 30 years = Double the money
A=2P———-(2)
Equate 1 and 2
P+SI=2P
SI=2P-P
SI=P————-(3)
WKT, SI= PTR/100
Equate 3 and SI
P=PTR/100
P=P*30*R/100
R=P*100/P*30
R=100/30 or 10/3 or 3(1/3) %
c
145.2
39 hrs 15 mins..
note:
he will not be having .45 mins for his lunch on saturday..
A. Rs. 410
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.
300%
slower train – 48 kmph = 40/3 m/s
say faster train, v m/s
therefore, {v-(40/3)}*180 = 600, => v= 60 kmph
5:6::7:10::6:5
=((5/6)/(7/10)/(6/5))
=((5/6)*(6/5)/(7/10))
=(1/(7/10))
=10/7
Put switch 1 on and leave it on for 2 minutes, then switch it off.
Put switch 2 on and leave it on, then walk into the room.
If the light is on, the answer is switch 2.
If the light is off but the bulb is warm when you feel it, the answer is switch 1.
If the light is off and the bulb is cold when you feel it, the answer is switch 3.
Dice
question is incomplete
20- buy 15 books
15- buy 20 books
Original price is 20.