@leotheking said:Inverted 6 can be considered as 9
u got it right
my take was
0,1,2,3,7,8
0,1,2,4,5,6
my take was
0,1,2,3,7,8
0,1,2,4,5,6
In ÎABC, D is the midpoint of BC. E is a point on AC such that AE : EC = 2 : 1 and F is a point on AB such that AF : FB = 3 : 1. Line segments AD and FE intersect at point O. What is the ratio of the area of ÎDOF to the area of ÎDOE?
(a) 8 : 9
(b) 9 : 8
(c) 3 : 4
(d) 4 : 3
Plz give answer alongwith explanation.
(a) 8 : 9
(b) 9 : 8
(c) 3 : 4
(d) 4 : 3
Plz give answer alongwith explanation.
@Exodia said:In ÎABC, D is the midpoint of BC. E is a point on AC such that AE : EC = 2 : 1 and F is a point on AB such that AF : FB = 3 : 1. Line segments AD and FE intersect at point O. What is the ratio of the area of ÎDOF to the area of ÎDOE?(a) 8 : 9 (b) 9 : 8 (c) 3 : 4 (d) 4 : 3Plz give answer alongwith explanation.
u can solve using coordinate geometry take origin which is not the Ideal way though,
Take origin as B(0,0) and c(12,0) and A(6,6_/3) considering Equilateral triangle now D=(6,0) as mid point and E,F can be found as the ratio is given ,Vertex O can be found
solving AD and FE straight lines equations ,now u know F,O,D,E it is easy to calc areas
Take origin as B(0,0) and c(12,0) and A(6,6_/3) considering Equilateral triangle now D=(6,0) as mid point and E,F can be found as the ratio is given ,Vertex O can be found
solving AD and FE straight lines equations ,now u know F,O,D,E it is easy to calc areas
@Exodia said:In ÎABC, D is the midpoint of BC. E is a point on AC such that AE : EC = 2 : 1 and F is a point on AB such that AF : FB = 3 : 1. Line segments AD and FE intersect at point O. What is the ratio of the area of ÎDOF to the area of ÎDOE?(a) 8 : 9 (b) 9 : 8 (c) 3 : 4 (d) 4 : 3Plz give answer alongwith explanation.
draw the diagram .
1) area of ÎABD =ÎACD
2)AREA OF ÎFBD : ÎAFD = 1:3
3) AREA OF ÎAED : ÎEDC = 2:1
This implies that area of ÎFBD : ÎAFD : ÎAED : ÎEDC= 3: 9 : 8 :4 .
=> ÎAFD : ÎAED = 9 : 8
=> as this Îs has same base AD so OF : OE = 9:8
1) area of ÎABD =ÎACD
2)AREA OF ÎFBD : ÎAFD = 1:3
3) AREA OF ÎAED : ÎEDC = 2:1
This implies that area of ÎFBD : ÎAFD : ÎAED : ÎEDC= 3: 9 : 8 :4 .
=> ÎAFD : ÎAED = 9 : 8
=> as this Îs has same base AD so OF : OE = 9:8
@Exodia said:In ÎABC, D is the midpoint of BC. E is a point on AC such that AE : EC = 2 : 1 and F is a point on AB such that AF : FB = 3 : 1. Line segments AD and FE intersect at point O. What is the ratio of the area of ÎDOF to the area of ÎDOE?(a) 8 : 9 (b) 9 : 8 (c) 3 : 4 (d) 4 : 3Plz give answer alongwith explanation.
OA: (c) 3:4
Anybody can give the explanation?
Anybody can give the explanation?
The average weight of 8 men is increased by 1.5 kg when one of the men who weigh 65 kg is replace by a new man. The weight of the new man is
a)76
b)76.5
c)76.7
d)77
@saurabhlumarrai said:The average weight of 8 men is increased by 1.5 kg when one of the men who weigh 65 kg is replace by a new man. The weight of the new man isa)76b)76.5c)76.7d)77
Ans. d) 77 kg
@saurabhlumarrai said:The average weight of 8 men is increased by 1.5 kg when one of the men who weigh 65 kg is replace by a new man. The weight of the new man isa)76b)76.5c)76.7d)77
77
A motorboat moves from point A to point B and back again. Both points being located on the river bank. If the speed of the boat in still water is doubled, then the trip from A to B and back again would take 20% of the original time . The ratio of the actual sped of motorboat to the speed of river is?
a (3/2)^1/2 b (3^1/2)/3 c 2/3 d 3/2
@IIM-A2013 said:A motorboat moves from point A to point B and back again. Both points being located on the river bank. If the speed of the boat in still water is doubled, then the trip from A to B and back again would take 20% of the original time . The ratio of the actual sped of motorboat to the speed of river is?a (3/2)^1/2 b (3^1/2)/3 c 2/3 d 3/2
Let a and be the speed of motorboat in still water and that of river.
As distance travelled is same in both cases, so time taken is inversely proportional to speeds in two scenarios.
Also speed in the two scenarios is Harmonic mean of upward and downward motion in both the scenarios.
Just putting all the expressions in place, we get
2(2a-b)(2a+b)/4a = 10(a-b)(a+b)/2a
i.e. 4a² - b² = 10a² - 10b²
i.e. 6a² = 9b²
i.e. a/b = â(3/2) i.e. option (a)
As distance travelled is same in both cases, so time taken is inversely proportional to speeds in two scenarios.
Also speed in the two scenarios is Harmonic mean of upward and downward motion in both the scenarios.
Just putting all the expressions in place, we get
2(2a-b)(2a+b)/4a = 10(a-b)(a+b)/2a
i.e. 4a² - b² = 10a² - 10b²
i.e. 6a² = 9b²
i.e. a/b = â(3/2) i.e. option (a)
@ishu1991 said:The calendar in the cell phone of Mr.Donny has malfunctioned and he does not like paper calendars in his office nor does he like to see the dates on any other electronic equipment. His assistant sees Mr. Donny stuck in the quandary. To help him, he glances across Mr. Donny âŹËs table and finds two different coloured dice but none of its faces have any numbers. He writes one number each on all the faces of both the dice so that Mr. Donny can set the dice each morning such that the top faces of the dice show the current date.What should be the numbers on each die to allow Mr.Donny to see any date?(Note: Single digits cannot be represented by just 1 die. On all days both dice must be used. So 9th would be 09).
1, 2, 3, 0, 7, 8
1, 2, 0, 4, 5, 6
6 works for both 6 and 9
1, 2, 0, 4, 5, 6
6 works for both 6 and 9
@Exodia said:In ÎABC, D is the midpoint of BC. E is a point on AC such that AE : EC = 2 : 1 and F is a point on AB such that AF : FB = 3 : 1. Line segments AD and FE intersect at point O. What is the ratio of the area of ÎDOF to the area of ÎDOE?(a) 8 : 9 (b) 9 : 8 (c) 3 : 4 (d) 4 : 3
Plz give answer alongwith explanation.
ratio of area of ÎDOF to the area of ÎDOE is same as the ratio of side OF to side OE which is 3:4. you can find it assigning weights.
@saurabhlumarrai said:The average weight of 8 men is increased by 1.5 kg when one of the men who weigh 65 kg is replace by a new man. The weight of the new man isa)76b)76.5c)76.7d)77
1.5*8 = 12
So that person is 12 kg more than 65
Hence 77
So that person is 12 kg more than 65
Hence 77
A jar full of whisky contains 40% of alcohol. A part of this whisky is replaced by another containing 19% alcohol and now the percentage of alcohol was found to be 26. The quantity of whisky replaced is:
@Faruq said:A jar full of whisky contains 40% of alcohol. A part of this whisky is replaced by another containing 19% alcohol and now the percentage of alcohol was found to be 26. The quantity of whisky replaced is:
2/3
@Faruq said:Ans is 2/3 Also explain the approach
Using alligation:
40 19
26
26
7 14
40 - 26 = 14 qty of 19%
26 - 19 = 7 qty of 40%
etc.
Q. A, B and C work together to complete some work. A takes thrice the time taken by the other two to complete the same work whereas B takes 6 times the time taken by the other two to complete the same. What part of the work was completed by C?
a)17/28
b)1/4
c)17/56
d)4/7
Plz solve
b)1/4
c)17/56
d)4/7
Plz solve
@sbharadwaj said:Q. A, B and C work together to complete some work. A takes thrice the time taken by the other two to complete the same work whereas B takes 6 times the time taken by the other two to complete the same. What part of the work was completed by C?a)17/28b)1/4c)17/56d)4/7Plz solve
1/a =(1/b + 1/c)*1/3 .....(1)
1/b=(1/a + 1/c) *1/6.....(2)
now put the value of (1) into (2)
1/b = 1/18b + 1/18c +1/6c
Solve it we will get
17C=4B
Again put the all values in (1)
4/51C +1/3C + 4/17C +1/C =1
C=17/28 Ans
1/b=(1/a + 1/c) *1/6.....(2)
now put the value of (1) into (2)
1/b = 1/18b + 1/18c +1/6c
Solve it we will get
17C=4B
Again put the all values in (1)
4/51C +1/3C + 4/17C +1/C =1
C=17/28 Ans