216)
ans is 15
no. of handshake= 15C2/2 =105
1)There are 4 boys and 3 girls. What is the probability the boys and girls sit alternately?
2). Two trains are 2 kms apart. Speed of one train is 20m/s and the other train is running at 30 m/s .Lengths of the trains are 200 and 300m. In how much time do the trains cross each other?
3)Four horses are tethered at the four corners of a square of side 14cm such that two horses along the same side can
just reach each other. They were able to graze the area in 11 days. How many days will they take in order to graze
the left out area?
4)Let A and B be two solid spheres such that the surface area of B is 300% higher than the surface area of A. The
volume of A is found to be k% lower than the volume of B. The value of k must be
A. 85.5
B. 92.5
C. 90.5
D. 87.5
5)if the ratio of work done by (x-1) men in (x+1)days to the work done by (x+2)men in (x-1)days is 9:10, then x is
equal to
A. 5
B. 6
C. 7
D. 8
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13 Answers
16)After a get-together every person present shakes the hand of every other person. If there were 105 hands-shakes
in all, how many persons were present in the party?
A 15
B 14
C 13
D 16
7)A class consists of 100 students, 25 of them are girls and 75 boys; 20 of them are rich and remaining poor; 40 of
them are fair complexioned. The probability of selecting a fair complexioned rich girl is:
A. 0.05
B. 0.04
C. 0.02
D. 0.08
8)Which of the following will come in place of the Question Mark (?) in the following sequence?
6C7, 5F10, 11J14, 15O19, ?
A 25U20
B 20U25
C 20U24
D 19U25
9). A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same
color is:
A 5/18
B 1/6
C 5/108
C 4/9
10)If the price of gold increases by 30%, find by how much the quantity of ornaments must be reduced so that the expenditure may remain the same as before?
A. 30%
B. 23 1/3 %
C. 20%
D. 19%
11)The amount of water (in ml) that should be added to reduce 9 ml lotion, containing 50% alcohol, to a lotion
containing 30% alcohol, is:
A. 5 ml
B. 4 ml
C. 3 ml
D. 6 ml
12)The average age of 8 persons in a committee is increased by 2 years when two men aged 35 years and 45 years
are substituted by two women. The average age of these two women is:
A. 52 years
B. 56 years
C. 48 years
D. 44 years
13)A mixture of 40 liters of milk and water contains 10% water. How much water should be added to this so that water may be 20% in the new mixture?
A. 6.5 liters
B. 5 liters
C. 4 liters
D. 7.5 liters
Plz solve these sums.
39"Plz show that u hv mde sum effort urself and we wil help u. if u r 2 lazy 2 attempt d sums, we r 2 lazy 2 help. Use http://answers.yahoo.com 4 HHW"
Otherwise sibal is always there.
494. (d)
area of b is 4 times area of a
rad of b is 2 times rad of a
vol of b is 8 times the vol of a
a is 7/8 times that is 87.5% less than vol of b.
mera kya if u are making us solve ur holiday homework....all that matters to me is that i am having a nice practice :P
491) no of ways they can sit= 7!
let us seat the girls and place boys in the left 4 places
thus, no of ways = 3! X 4!
probability= 3! X 4!7!=135
492)for question number 2 please clarify wether the distance 2 km is the dist b/w head of 2 trains or tail of the one in front and head of the tain behind.
if 2 km is the dist b/w tail of the one in front and head of the tain behind,
let the time taken to overtake be t.
distance travelled by first train= 20t
distance travelled by second train= 30t
by the problem,
30t=20t+200+2000+300
giving, t= 250 seconds= 416mins.
493) the length of each side is 14 cm.
so area available to each tethered horse=quadrant of radius 7cm = 14Ï€X(7)2=1544 cm2.
total area grazed in 11 days= 4X1544 cm2= 154 cm2.
total area present in square= 194 cm2.
now,
case-1::the horses are still tethered to the corners, time taken to graze the rest grass is ∞ days. [3][3]
case-2:: the tetherings of the horses are opened.
time taken to graze left 50 cm2= 5014=347days ~ 4 days.
495) actually the given is (x+1)(x-1):(x+2)(x-1)=9:10
so, x=0,8
we can ignore value 0
thus answer is 8
49n persons in party, shakes hand with n-1 people...
but a shaking hand with b is equivalent to b shaking hand with a.
so no of handshakes= n(n-1)/2 = 105
n(n-1)= 210
n=15.
496)n persons in party, shakes hand with n-1 people...
but a shaking hand with b is equivalent to b shaking hand with a.
so no of handshakes= n(n-1)/2 = 105
n(n-1)= 210
n=15.
496)i use venn diagram for this...
P= (no of rich fair complextioned girls)/100
hehehehe...for me the probability is 1 :P:P