Jonny invested $1,500 at a bank that gave him a rate of 4%. He saved that money for 30 months. How much Interest did he earn?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

The radius of a sphere is 3 inches. which represents the volume of the sphere?

Maria found the least common multiple of 6 and 15. her work is shown below. multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, . . multiples of 15: 15, 30, 45, 60, . . the least common multiple is 60. what is maria's error?