Can someone explain how to solve this step by step with answer? you.

a)

well, she put 4000, and she earned in interest 960, so her accumulated amount is just their sum, 4960.

b)

now, it doesn't say, so we're assuming is simple interest, as opposed to compound interest.

c)

let's make the rate 1% greater then, and check

77

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.