Time, Work & Speed
3 questions available
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Q1.Several number of cows on a farm consume the food in 150 days. If we reduce the number of cows by 10, then the food lasts for 160 days. How many cows were there on the farm in the beginning?
Correct Answer: B
Using inverse proportion (cows x days = constant): if x cows eat in 150 days, (x-10) cows eat in 160 days. Solving x(150) = (x-10)(160) gives x = 160.
Q2.The forest workers plant 200 trees in one month (30 days). When 20 workers were sent away, 200 trees were planted in 40 days by this second group. How many workers were there in the first group?
Correct Answer: C
Using inverse work-rate proportion: workers x days is constant when trees planted are equal, solving gives 80 workers initially.
Q3.16 men and 12 women can complete a work in 20 days. 18 women can complete the same work in 40 days. In how many days will 12 men and 27 women complete the same work?
Correct Answer: A
Setting up work-rate equations from the given data and solving for 12 men and 27 women gives 16 days.