There are 40 students in a classroom, 9/20 of them are boys and 4/5 of them are right-handed. How many right-handed boys are there in the classroom?
  • a)
    Between 10 and 32.
  • b)
    Between 14 and 32.
  • c)
    Between 10 and 18.
  • d)
    Between 14 and 18.
  • e)
    Between 18 and 36
Correct answer is option 'C'. Can you explain this answer?

Related Test

Given that there are 18 boys (9/20*40=18) and 22 girls in the class. Also we know that out of 40 students 32 are right-handed (4/5*40=32).

Maximum number of right-handed boys possible is if ALL 18 boys are right-handed;
Minimum number of right-handed boys possible is if ALL 22 girls are right-handed, so in this case 32-22=10 boys would be right-handed.

Phada Guy
Mar 22, 2020
This is because, 9/20 of 40 = 18. we have 18 boys in all and 4/5 of 18 is approximately 14.4 which lies between 10 and 18

Given that there are 18 boys (9/20*40=18) and 22 girls in the class. Also we know thatout of 40 students32 are right-handed (4/5*40=32).Maximum number of right-handed boys possible is if ALL18 boys are right-handed;Minimum number of right-handed boys possible is if ALL 22 girls are right-handed, so in this case 32-22=10 boys would be right-handed.

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Given that there are 18 boys (9/20*40=18) and 22 girls in the class. Also we know thatout of 40 students32 are right-handed (4/5*40=32).Maximum number of right-handed boys possible is if ALL18 boys are right-handed;Minimum number of right-handed boys possible is if ALL 22 girls are right-handed, so in this case 32-22=10 boys would be right-handed.