Search found 154 matches
Hi karim.nazmy,
Here's another approach:
We can consider 3 scenarios:
g:green
y:yellow
r:red
gg + yy + rr
(4/9)(3/8) + (2/9)(1/8) + (3/9)(2/8) = 5/18
- by talaangoshtari
Sun Oct 18, 2015 1:54 am- Forum: Problem Solving
- Topic: Probability Question
- Replies: 3
- Views: 1184
Hi maakya, First name the point on the diagonal, E. Now we can see that the triangle BCE and the triangle BCD are similar, since BC is in both triangles and both triangles have the angle that is equal to 90. EC/CD = BC/BD = BE/BC EC/15 = 20/25= BE/20 EC = 12, BE = 16 Therefore, Area = EC.BE/2 = (16)...
- by talaangoshtari
Sun Oct 18, 2015 1:39 am- Forum: Problem Solving
- Topic: Area of Shaded Region
- Replies: 2
- Views: 1166
Hi Marty Murray,
I had difficulty in understanding the solution of this problem:
S = {([twins], boy), ([twins], girl), (boy, [twins]), (girl, [twins])}
P((boy, [twins])) = 1/4
- by talaangoshtari
Sat Oct 17, 2015 9:10 pm- Forum: Problem Solving
- Topic: Probability
- Replies: 6
- Views: 1561
Probability
A family with 3 children has one twins. What is the probability that the oldest child is a boy and he is not a twin himself?
A. 1/2
B. 1/3
C. 1/4
D. 3/4
E. 1/5
- by talaangoshtari
Sat Oct 17, 2015 1:34 am- Forum: Problem Solving
- Topic: Probability
- Replies: 6
- Views: 1561
- by talaangoshtari
Fri Oct 16, 2015 1:13 am- Forum: Problem Solving
- Topic: Time And Distance Problem
- Replies: 3
- Views: 2138
Hi parthdpatel,
We know that rt=d:
Suppose the time taken for the first part of the trip is t1, and the time taken for the second part of the trip is t2,
4t1+5t2=35
5t1+4t2=37
So, t1=5 and t2=3, and the sum is equal to 8.
- by talaangoshtari
Fri Oct 16, 2015 12:12 am- Forum: Problem Solving
- Topic: Time And Distance Problem
- Replies: 9
- Views: 7024
Hi Rich,
yes, this question has 3 correct answers, but I didn't understand the process of solving.
1. 4
2. 6
3. 8
4. 10
5. 12
A. 1,2
B. 2,3,4
C. 3,4
D. 3,4,5
E. None
- by talaangoshtari
Thu Oct 15, 2015 9:44 am- Forum: Problem Solving
- Topic: Average
- Replies: 5
- Views: 3467
Average
The average age of the buildings on a certain city block is greater than 40 years old. If four of the buildings were built two years ago and none of the buildings are more than 80 years old, which of the folowing could be the number of buildings on the block?
A. 4
B. 6
C. 8
D. 10
E. 12
- by talaangoshtari
Thu Oct 15, 2015 6:57 am- Forum: Problem Solving
- Topic: Average
- Replies: 5
- Views: 3467
- by talaangoshtari
Wed Oct 07, 2015 8:33 am- Forum: Problem Solving
- Topic: A cloth merchant
- Replies: 2
- Views: 1089
A cloth merchant
A cloth merchant sells cloth at cost price but while selling he uses 80 cm scale instead of a meter scale. What is his profit percentage?
A. 20%
B. 25%
C. 30%
D. 35%
E. 40%
- by talaangoshtari
Wed Oct 07, 2015 7:16 am- Forum: Problem Solving
- Topic: A cloth merchant
- Replies: 2
- Views: 1089
- by talaangoshtari
Tue Oct 06, 2015 10:53 pm- Forum: Problem Solving
- Topic: Percent Problem
- Replies: 1
- Views: 1016
Two trains
Two trains, train Alpha and Beta run in opposite directions on a circular track. Train Alpha travels at a rate of 4Ï€ miles per hour and Train Beta runs at a rate of 6Ï€ miles per hour. If the track has a radius of 6 miles and the trains both start from point Delta at the same time, how long, in hou...
- by talaangoshtari
Mon Oct 05, 2015 8:26 pm- Forum: Problem Solving
- Topic: Two trains
- Replies: 1
- Views: 1811
Average
A set of consecutive positive integers beginning with 1 is written on the blackboard. A student came along and erased one number. The average of the remaining numbers is 35 7/17. What was the number erased?
A. 7
B. 8
C. 9
D. 10
E. 11
- by talaangoshtari
Mon Oct 05, 2015 3:25 am- Forum: Problem Solving
- Topic: Average
- Replies: 3
- Views: 9538
Geometry
A circle is inscribed in an equilateral triangle, such that the two figures touch at exactly 3 points, one on each side of the triangle. Which of the following is closest to the percent of the area of the triangle that lies within the circle?
(A) 50%
(B) 55%
(C) 60%
(D) 65%
(E) 70%
- by talaangoshtari
Sat Sep 26, 2015 9:43 pm- Forum: Problem Solving
- Topic: Geometry
- Replies: 1
- Views: 1372
- by talaangoshtari
Sat Sep 26, 2015 12:38 am- Forum: Problem Solving
- Topic: Arranging the letters
- Replies: 4
- Views: 1875