# Time and Work Practice Set

 1. A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is: — A किसी कार्य को 15 दिनों में कर सकता है और B 20 दिनों में कर सकता है। यदि वे 4 दिनों के लिए एक साथ काम करते हैं, तो शेष कार्य का अंश है: A. 1⁄4 B. 1⁄10 C. 7⁄15 D. 8⁄15 Answer: Option D Explanation: A’s 1 day’s work = 1⁄15 B’s 1 day’s work = 1⁄20 (A + B)’s 1 day’s work = [1⁄15 + 1⁄20] = 7⁄60 (A + B)’s 4 day’s work = [7⁄60 × 4] = 7⁄15 Therefore, Remaining work = [1 – 7⁄15] = 8⁄15 View / Hide Answer

 2. A can lay railway track between two given stations in 16 days and B can do the same job in 12 days, with help of C, they did the job in 4 days only. Then, C alone can do the job in: — A 16 दिनों में दो स्टेशनों के बीच रेलवे ट्रैक रख सकता है और B 12 दिनों में यही काम कर सकता है, C की मदद से उन्होंने केवल 4 दिनों में यही काम कर दिया। अकेले C यही काम कितने दिनों में कर सकता है: A. 9 1/5 B. 9 2/5 C. 9 3/5 D. 10 Answer: Option C Explanation:(A + B + C)’s 1 day’s work = 1⁄4 A’s 1 day’s work = 1⁄16 B’s 1 day’s work = 1⁄12 C’s 1 day’s work = 1⁄4 – [1⁄16 + 1⁄12] = [1⁄4 – 7⁄48] = 5⁄48 So, C alone can do the work in 48⁄5 = 93⁄5 View / Hide Answer

 3. A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if he is assisted by B and C on every third day? — A, B और C क्रमशः 20, 30 और 60 दिनों में एक काम कर सकते हैं। प्रत्येक तीसरे दिन B और C द्वारा सहायता प्राप्त होने पर A कितने दिनों में यह काम कर सकता है ? A. 12 days B. 15 days C. 16 days D. 18 days Answer: Option B Explanation:A’s 2 day’s work = [1⁄20 × 2] = 1⁄10 (A + B + C)’s 1 day’s work = [1⁄20 + 1⁄30 + 1⁄60] = 6⁄60 = 1⁄10 Work done in 3 days = [1⁄10 + 1⁄10] = 1⁄5 Now, 1⁄5 work is done in 3 days. Whole work will be done in (3 × 5) = 15 days View / Hide Answer

 4. A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in: — A कार्यकर्ता के रूप में B से तीन गुना अच्छा है और इसलिए B से 60 दिन कम में काम खत्म करने में सक्षम है। साथ काम करके दोनों इस काम को कितने दिन में खत्म कर सकते है ? A. 20 days B. 22 1/2 days C. 25 days D. 30 days Answer: Option B Explanation:Ratio of times taken by A and B = 1 : 3 The time difference is (3 – 1) 2 days while B take 3 days and A takes 1 day. If difference of time is 2 days, B takes 3 days. If difference of time is 60 days, B takes [3⁄2 × 60] = 90 days So, A takes 30 days to do the work. A’s 1 day’s work = 1⁄30 B’s 1 day’s work = 1⁄90 (A + B)’s 1 day’s work = [1⁄30 + 1⁄90] = 4⁄90 = 2⁄45 A and B together can do the work in 45⁄2 = 221⁄2 days View / Hide Answer

 5. A alone can do a piece of work in 6 days and B alone 8 days. A and B undertook to do it for Rs.3200. With the help of C, they completed the work in 3 days. How much is to be paid to C? — A अकेले किसी काम को 6 दिनों में और B अकेले 8 दिन में कर सकते हैं। A और B ने C की मदद से इसे 3200 रुपये के लिए किया। उन्होंने काम को 3 दिनों में पूरा कर लिया। C को कितना भुगतान करना है? A. Rs.375 B. Rs.400 C. Rs.600 D. Rs.800 Answer: Option B Explanation:C’s 1 day’s work = 1⁄3 – [1⁄6 + 1⁄8] = 1⁄3 – 7⁄24 = 1⁄24 A’s wages : B’s wages : C’s wages = 1⁄6 : 1⁄8 : 1⁄24 = 4 : 3 : 1 C’s share (for 3 days) = Rs.[3 × 1⁄24 × 3200] = Rs.400 View / Hide Answer

 6. If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys in doing the same type of work will be: — यदि 6 पुरुष और 8 लड़के एक काम को 10 दिनों में कर सकते हैं, जबकि 26 पुरुष और 48 लड़के 2 दिनों में कर सकते हैं, तो उसी तरह के काम करने में 15 पुरुषों और 20 लड़कों द्वारा लिया गया समय होगा: A. 4 days B. 5 days C. 6 days D. 7 days Answer: Option A Explanation:Let 1 man’s 1 day’s work = x and 1 boy’s 1 day’s work = y Then, 6x + 8y = 1⁄10 and 26x + 48y = 1⁄2 Solving these two equations, we get : x = 1⁄100 and y = 1⁄200 (15 men + 20 boy)’s 1 day’s work = [15⁄100 + 20⁄200] = 1/4 15 men and 20 boys can do the work in 4 days. View / Hide Answer