Understanding the Class Composition
The problem states there are 90 students in total in the class. It also mentions that the number of girls is double the number of boys. Let's denote the number of boys as B and the number of girls as G.
- Total students = 90
- Relationship between girls and boys: $G = 2 \times B$
We can use these two pieces of information to find the exact number of boys and girls. The total number of students is the sum of boys and girls:
$ B + G = 90 $
Now, substitute the relationship $G = 2 \times B$ into the total students equation:
$ B + (2 \times B) = 90 $
Combine the terms with B:
$ 3 \times B = 90 $
To find the number of boys (B), divide the total students by 3:
$ B = \frac{90}{3} $
$ B = 30 $
So, there are 30 boys in the class. Now we can calculate the number of girls:
$ G = 2 \times B = 2 \times 30 $
$ G = 60 $
Therefore, the class consists of 30 boys and 60 girls.
Analyzing Rahul's Position and Peers
Rahul's position in the class ranking from the top is given as 20th. This means that there are 19 students who are ranked ahead of him.
- Rahul's rank from the top = 20
- Number of students ahead of Rahul = Rahul's rank - 1
- Number of students ahead of Rahul = $20 - 1 = 19$
The problem also states that 15 girls are ahead of Rahul among these 19 students.
- Number of girls ahead of Rahul = 15
To find out how many boys are ahead of Rahul, we subtract the number of girls ahead of him from the total number of students ahead of him:
$ \text{Boys ahead of Rahul} = (\text{Total students ahead of Rahul}) - (\text{Girls ahead of Rahul}) $
$ \text{Boys ahead of Rahul} = 19 - 15 $
$ \text{Boys ahead of Rahul} = 4 $
This tells us that there are 4 boys positioned in the ranking before Rahul.
Calculating the Number of Boys Behind Rahul
We have determined the total number of boys in the class and the number of boys who are ranked ahead of Rahul. To find the number of boys ranked behind Rahul, we need to subtract the boys ahead of him from the total number of boys in the class.
- Total number of boys in the class = 30
- Number of boys ahead of Rahul = 4
The calculation is as follows:
$ \text{Boys behind Rahul} = (\text{Total boys in the class}) - (\text{Boys ahead of Rahul}) $
$ \text{Boys behind Rahul} = 30 - 4 $
$ \text{Boys behind Rahul} = 26 $
Based on these calculations, there are 26 boys behind Rahul in the class ranking.
Similar Questions
- In a race of 40 runners, if Anu is placed 15th, how many runners are ahead of her?
Horse E was running ahead of horse D in the middle of the race. Horse C was ahead of horse A but behind horse B. Horse A was running ahead of horse E. From this point on, the fourth-placed horse took the lead and won the race. If the positions of the other horses remained the same, which horse was in the middle at the end of the race?
Ina class of 64 students, Komal’s rank is 6 positions lower (i.e. towards bottom) than her friend Shikha, who is at the 59 th position from the end. What is Komal’s rank from the top in the class?
A is taller than B. C and D are of equal height. E is shorter than B but taller than D. F is shorter than C, who is shorter than B. Who is the shortest among all?
Five friends took a test. Payal scored more than Komal. Reena scored less than Payal. Simi scored more than Tanu but less than Komal. Who among them scored the highest?
In a class, 24 students have scored more marks than Vineet, whereas 19 students have scored lesser marks than Surbhi. Arti has scored more marks than Surbhi, but lesser marks than Vineeet. Arti has scored lesser marks than 29 students and more marks than 26 students. How many total students are there in the class ?
There are six fruits A, B, C, D, E and F. A is sweeter than D but not as sweet as B. E and B are not as sweet as F. D is sweeter than C. E is sweeter than A. Which fruit among the six is the least sweet?
O, P, Q, R, S and T are six sisters who are good at knitting. T is better than S. Q is better than R. O is better than P. Q is not as good as P. S is better than O. Who among the six is the best at knitting?
J, K, L, M, N and O are six colleagues working in an NGO. J earns more than L but less than M. K earns more than J but less than N. N earns less than O but more than M. K earns less than M. Who among the six earns the most?
Rama is taller than Saho. Manoj is shorter than Dinesh. Dinesh is taller than Tara but shorter than Saho. Kailash is shorter than Tara but taller than Manoj. Tara is shorter than Saho. Who is the shortest?
Important Questions from Ordering and Ranking
A medical representative plans to visit each of six hospitals — A, B, C, D, E and F — exactly once during the course of one day. He is setting up his schedule for the day according to the following conditions:
i. He must visit A before B and E.
ii. He must visit B before D.
iii. The third hospital he visits must be C.
Which of the following could be the possible order in which the medical representative visits the six hospitals?Sonam is older than Renu. Komal is younger than Renu. Priya is older than Sonam. Who is the eldest of them?
Five men P, Q, R, S and T are reading a newspaper. The one who reads it first, gives it to T. The one who reads it last, had taken it from R. Q is not the first or last one to read it. There were two readers between P and R. Who is the third one to have read the newspaper?
P, Q, R, S, T and U are standing in a queue. Q is just ahead of P. S is just behind T. U is NOT near R, who is separated from Q by two persons. Who is standing at the front of the queue?
Five students took part in a cycling competition. Robert finished before Monish but behind Gunjan. Anil finished before Sunil but behind Monish.
Who won the competition?
