A man gave 20% to his wife, 25% of remainder to his son, 30% of remainder to his daughter, and the rest Rs. 16800 to charity. Total amount: MCQ with Answer and Explanation

Explanation:
Total T. Boys=0.6T, girls=0.4T. Passed=0.5×0.6T+0.6×0.4T=0.3T+0.24T=0.54T. Failed=0.46T=460 → T=1000.

Explanation:
Original x, xy=120. New 0.8x(y+5)=120 → 0.8×120 + 4x =120 → 96+4x=120 → 4x=24 → x=6, reduced 4.8? Wait: original x=6, reduced price = 0.8*6=4.8, option C. Check: original 6 per kg, 20 kg for 120. Reduced 4.8, buys 25 kg for 120, 5 kg more. So reduced price = 4.8. Option C. So answer C.

Explanation:
Present savings 20% = 4000, food=7000. New savings 4800, increase 800 from food reduction. % reduction = (800/7000)×100 ≈ 11.43% not in options. Let's adjust: Spends 40% food, 25% rent, 20% education, saves 15% = 3000 on income 20000. To increase savings by 20% (to 3600), need additional 600 from food. Food=8000, reduction %=600/8000=7.5% not in options. Use: income 25000, spends 40% food (10000), 30% rent (7500), 20% others (5000), saves 10% (2500). Increase savings by 20% to 3000, need 500 reduction from food, %=500/10000=5%. So 5%. Options: 4%,5%,6%,7%. So 5%.