UPSC Prelims 2016 · CSAT
Question 20: Basic Numeracy
There is an order of 19000 quantity of a particular product from a customer. The firm produces 1000 quantity of that product per day out of which 5% are unfit for sale. In how many days will the order be completed ?
AnswerUPSC’s answer is (c).
5% of 1000 is 50 unfit, so 950 units a day are fit for sale. Days needed = 19000 / 950 = 20. Remember: apply the loss first, then divide the order by the usable daily output. Using the full 1000 a day would give 19 days, which ignores the rejects.
How you could have got this
No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) 18 days gives only 17,100 fit units.
- (b) 19 days gives only 18,050 fit units.
- (c) Right: 20 x 950 = 19,000.
- (d) 22 days is more than needed.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2016, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.