Ratio and Proportion with Explanation

Q15. 100 kg of solution A is mixed with 60 kg of solution B. If solution A has tin and copper in the ratio 1 : 4 and solution B has lead and tin in the ratio 3 : 2, then what is the amount of tin in the new solution?

A. 70 kg B. 36 kg
C. 56 kg D. 44 kg

Q16. A purse has Rs. 10, Rs. 5, and Rs. 2 coins in the ratio 9 : 5 : 4 amounting to Rs. 1866. Find the number of Rs. 10 coins in the purse?

A. 15 B. 20
C. 18 D. 16

Q17. The average age of three friends is 25 years. Their ages are in the proportion 5 : 7 : 3. Find the age of eldest friend?

A. 35 years B. 21 years
C. 18 years D. 37 years