Question 81
The average age of 120 members of a society is 60.7 years. By addition of 30 new members, the average age becomes 56.3 years. What is the average age (in years) of newly joined members?
Solution
Average age of 120 members of the society = 60.7 years
=> Total age of 120 members = $$120\times60.7=7284$$ years
Let the average age of 30 new members = $$x$$ years
=> Total age of the 30 members = $$30x$$ years
According to ques, new average = 56.3 years
=> $$\frac{7284+30x}{(120+30)}=56.3$$
=> $$7284+30x=56.3\times150=8445$$
=> $$30x=8445-7284=1161$$
=> $$x=\frac{1161}{30}=38.7$$
=> Ans - (D)
Video Solution
Create a FREE account and get:
- Free SSC Study Material - 18000 Questions
- 230+ SSC previous papers with solutions PDF
- 100+ SSC Online Tests for Free
CAT Quant Questions | CAT Quantitative Ability
CAT Percentages QuestionsCAT Averages, Ratio and Proportion QuestionsCAT Mensuration QuestionsCAT Quadratic Equations QuestionsCAT Remainders Questions
CAT DILR Questions | LRDI Questions For CAT
CAT Quant Based LR QuestionsCAT Special Charts QuestionsCAT Routes And Networks QuestionsCAT Coins and Weights QuestionsCAT 2D & 3D LR Questions
