GMAT Simple Interest

In how many years will a sum of money doubles itself at 5% per annum simple interest?

A sum of money becomes thrice itself in 5 years at simple interest. In how many years will it become six time at the same rate?

A sum of money becomes double itself in 8 years at simple interest. How many times will it become in 16 years at the same rate?

A part of certain sum of money is invested at 9% per annum and the rest at 12% per annum, if the interest earned in each case for the same period is equal, then ratio of the sums invested is?

Equal amounts of money are deposited in two banks each at 15% per annum for 3.5 years and 5 years respectively. If the difference between their interest is $144 find the each sum.

A sum of $2665 is lent into two parts so that the interest on the first part for 8 years at 3% per annum may be equal to the interest on the second part for 3 years at 5% per annum. Find the second sum.

If A lends $3500 to B at 10% per annum and B lends the same sum to C at 11.5% per annum then the gain of B in a period of 3 years is?

A person lent a certain sum of money at 4% per annum at simple interest and in 8 years the interest amounted to $340 less than the sum lent. What was the sum lent?

If $450 amount to $540 in 4 years, what will it amount to in 6 years at the same rate % per annum?

$800 amounts to $920 in 3 years at simple interest. If the interest rate is increased by 3%, it would amount to how much?