एक कार्यालय में 72% कर्मचारियों को ठंडे पेय पसंद हैं, 44% कर्मचारियों को चाय पसंद है और प्रत्येक कर्मचारी को चाय या ठंडे पेय में से कम से कम एक चीज़ पसंद है। यदि 40 कर्मचारियों को चाय और ठंडे पेय दोनों पसंद हैं, तो उस कार्यालय में कुल कितने कर्मचारी हैं?

In a class of 90 students, 60 opted for Mathematics, 50 opted for Science, and 20 opted for both. How many students opted for Science only?

In a college, 60% of students failed in Mathematics, 50% failed in Physics, 55% failed in Chemistry, and 45% failed in Biology. 10% of students failed in all four subjects. 18% of students failed in Mathematics, Physics, and Chemistry. 15% failed in Physics, Chemistry, and Biology. 12% failed in Mathematics, Chemistry, and Biology. The percentage of students failing in exactly two subjects including Physics but excluding Mathematics is 15%. The percentage of students failing in exactly two subjects including Chemistry but excluding Biology is 12%. 20% of students failed in Mathematics and Physics only. 18% of students failed in Chemistry and Biology only. Find the percentage of students who failed in only Mathematics.