Mathematics/General Ability MCQs
Topic Notes: Mathematics/General Ability
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
131
100 men have food for 45 days. After 15 days, some men leave, and the food lasts for 40 more days. How many men left?
Answer:
25 men
After 15 days, food left = 100 × 30 = 3000 man-days. For 40 days, remaining men = 3000 / 40 = 75. Men left = 100 - 75 = 25 men.
132
800 soldiers have food for 25 days. After 5 days, some soldiers leave, and the food lasts for 25 more days. How many soldiers left?
Answer:
160
Food left after 5 days = 800 × 20 = 16000 soldier-days. If it lasts 25 days, remaining soldiers = 16000 / 25 = 640. Soldiers left = 800 - 640 = 160.
133
A garrison of 250 men has food for 40 days. After 10 days, some men join, and the food lasts for 20 more days. Find the number of new men.
Answer:
125 men
Food left after 10 days = 250 × 30 = 7500 man-days. For 20 days, total men = 7500 / 20 = 375. Men joined = 375 - 250 = 125 men.
134
60 men have provisions for 30 days. After 10 days, some men join, and the provisions last for 15 more days. How many men joined?
Answer:
20 men
After 10 days, provisions left = 60 × 20 = 1200 man-days. For 15 days, total men = 1200 / 15 = 80. Men joined = 80 - 60 = 20 men.
135
500 men have food for 30 days. After 5 days, some men leave, and the food lasts for 50 more days. Find the number of men who left.
Answer:
250 men
After 5 days, food left = 500 × 25 = 12500 man-days. If it lasts 50 days, remaining men = 12500 / 50 = 250. Men left = 500 - 250 = 250 men.
136
A fort of 120 men has provisions for 45 days. After 15 days, a certain number of men leave, and the provisions last for 40 more days. How many men left?
Answer:
30 men
After 15 days, provisions left = 120 × 30 = 3600 man-days. If they last 40 days, remaining men = 3600 / 40 = 90. Men left = 120 - 90 = 30 men.
137
400 soldiers have food for 60 days. After 20 days, some soldiers leave, and the remaining food lasts for 50 more days. How many soldiers left?
Answer:
80
After 20 days, food left = 400 × 40 = 16000 soldier-days. If it lasts 50 days, remaining soldiers = 16000 / 50 = 320. Soldiers left = 400 - 320 = 80.
138
A camp of 300 men has food for 35 days. After 15 days, some men join, causing the food to last only 15 more days. Find the number of men who joined.
Answer:
100 men
After 15 days, food left = 300 × 20 = 6000 man-days. If it lasts 15 days, total men = 6000 / 15 = 400. Men joined = 400 - 300 = 100 men.
139
150 men have provisions for 50 days. After 20 days, some men join, and the provisions last for 20 more days. How many men joined?
Answer:
75 men
After 20 days, provisions left = 150 × 30 = 4500 man-days. Let total men be M. M × 20 = 4500. M = 225. Men joined = 225 - 150 = 75 men.
140
A garrison of 200 men has food for 40 days. After 10 days, a reinforcement joins them, and the food then lasts for 20 more days. How many men joined?
Answer:
100 men
After 10 days, remaining food = 200 × 30 = 6000 man-days. Let new number of men be M. M × 20 = 6000. M = 300 men. Men joined = 300 - 200 = 100 men.