UPSC Prelims 2016 · CSAT
Question 33: Basic Numeracy
The monthly average salary paid to all the employees of a company was Rs. 5000. The monthly average salary paid to male and female employees was Rs. 5200 and Rs. 4200 respectively. Then the percentage of males employed in the company is :
AnswerUPSC’s answer is (b).
Use the weighted average. Let the male share be m: 5200m + 4200(1 - m) = 5000. So 1000m = 800 and m = 0.8, i.e. 80%. Alligation check: the gaps from the overall average are 200 (males) and 800 (females), so males to females = 800 : 200 = 4 : 1, which is 80% males.
Why each option is right or wrong
- (a) 75% males gives an average of Rs 4,950.
- (b) Right: 80% males gives exactly Rs 5,000.
- (c) 85% males gives Rs 5,050.
- (d) 90% males gives Rs 5,100.
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.