The GMAT Forum

Simple Interest:

SI = PRT / 100

A = P + SI

A student invests 4000, part at 6% and part at 7%. The income from these investments in 1 year is 250. Find the amount invested at 7%.

250 = I1 + I2

Let x be the amount invested for 7%.

250 = (4000-x)*6 / 100 + x*7/100

x = 1000.

A total of 1200$ is deposited in 2 semi annual accounts for one year. Part at 5% and remainder at 10%. If 72$ was earned as interest How much was deposited at 5%?

72 = x * 5 * 0.5 / 100 + (1200-x) * 10 * 0.5 / 100