Work can be completed by men in 15 days. 5 men leave work after 3 days. The remaining work was completed in 18 days. What is the value of N?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 15
⇒ men1 x days1 = men2 ×days2
⇒ N × 15 = N × 3 + (N - 5) × 18
⇒ 15N = 3N + 18N - 90
⇒ 15N = 21N - 90
⇒ 21N - 15N = 90
⇒ 6N = 90
⇒ N = 15