Question

60 विद्यार्थियों की एक कक्षा में लड़कों की
संख्या लड़कियों से दुगनी है। रीना का क्रमांक
प्रारम्भ से 17वाँ है। यदि उसके आगे 9 लड़के
हों, तो उसके बाद कितनी लड़कियाँ हैं ?
(A) 12
(B) 13
(C) 31
(D) 21​

Answer 1

Answer:

(A) 12

Step-by-step explanation:

This means that there are 9 Boys and 7 girls ahead of Rina.

And including Rina 8 girls.

Thus,

20-8

=12.

(refer to the attached image)

Answer 2

There are 12 girls behind Rina.

Step-by-step explanation:

According to the given information,

the total number of students in the class is 17. Now, this class has both boys as well as girls. Rina happens to be one of the girls present in the class of 60 boys and girls.

Also, given that, Rina is 17 places back in the class.

Now, out of this, there are 9 boys ahead of Rina.

This means that, out of 16 students, there are 9 boys.

Thus, the number of girls ahead of her = 16 - 9 = 7

Thus, there are 9 boys and 7 girls ahead of Rina.

Now, in the class, the number of boys is equal to twice the number of girls, that is the number of boys  = 2 (number of girls).

Thus, if 60 is the number of students, 60 = 40 + 20, that is the number of boys is 40 and the number of girls is 20.

That means, the number of girls behind Rina is,

Total number of girls in the class  - (Number of girls ahead of Rina + Rina)

=20 - 8

12.

Thus, there are 12 girls behind Rina.

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