Question

10. Average cost of 10 pens is 200 and average cost of 10 pencils is * 100. Find the average cost of all pens and pencils. RRB NTPC (Phase 1) 2016 (1) 15 (2) 150 (3) 115 (4) None of these

11th - 12th Class

Maths

Solution

211

4.0 (1 ratings)

10. (2) According to the question, Total cost of 10 pens ( =10 times 200=₹ 2000 ) Total cost of 10 pencils ( =10 times 100=₹ 1000 ) : Average cost of all pens and pencils [ =frac{2000+1000}{10+10}=frac{3000}{20}=₹ 150 ]