if 120% of a is equal to 80% of b, then $${b+a}\over {b-a}$$ is equal to

What is the compound interest on ₹24,000 for 2 years at the rate of 10% per annum, if interest is compounded annually?

The price of a variety of a commodity is ₹7/kg and that of another is ₹12/kg. Find the ratio in which two varieties should be mixed so that the price of the mixture is ₹10/kg.

The following table shows the number of laptops sold from five different stores in a city on five days of a given week.

What is the ratio of the total number of computers sold from store S on Tuesday, Monday and Sunday taken together to that sold from store P on Tuesday, Wednesday and Thursday taken together?

The ratio of the number of boys and girls in the parade of students of a school is 9 : 7 respectively and the total number of students is 256. Find the number of girls?

The numerator of a fraction is 3 more than the denominator. When 5 is added to the numerator and 2 is subtracted from the denominator, the fraction becomes $$8\over 3$$ . When the original fraction is divided by$$5{1\over 2}$$, the fraction so obtained is:

A boat covers a certain distance against the stream in 9 hours 36 min and it covers the same distance along the stream in 6 hours. What is the ratio of the speed of the boat in still water to that of the stream?

A and B started a business in partnership. The ratio between the investments of A and B was 5: 4. If A invested for 12 months and at the end of the year the ratio of prot was 15: 8, then for how much time B invested?