Seema works at a rate such that she can finish a work in 28 h, but she works at this rate for 7 h only. After diet, she works at a rate such that she can finish the remaining work in 16 h. If seema is to finish this work at a stretch how many hours (total) will she take to finish this work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 19.
Given:
Seema works at a rate such that she can finish a work in 28 h
Formula used:
Total work = efficiency × time ----- (1)
Calculations:
Let the efficiency of seema be x
Using equation (1), we get
⇒ Total work = 28x
Work completed in 7 hours = 7x
Remaining work = 28x - 7x = 21x
Seema complete the remaining work in 16 hours = 28x/16 = 7x/4
Time required to complete the remaining work = 21x/(7x/4) = 12 hours
Required total time = 7 + 12 = 19 hours