David earns 4% for the money he has in savings. let a represent how much he has in his account. write two expressions that can be used to calculate the amount of money in his account after one month

I = a/300

A = (300I + a)/300

Step-by-step explanation:

David earns 4% for the money he has in savings. Let the amount that he has initially be a. This means that his principal is a. So

P = a

The rate at which he is earning interest on the principal is 4%. Therefore,

R = 4℅

We want to calculate the amount of money in his account after one month. This means that time,

t = 1/12 (12months make a year)

The amount of money in his account after one month will be the interest earned in one month + the initial amount in the account.

To determine the interest, we will apply the simple interest formula,

I = PRT/100

Where I = interest

P = principal

T = time

The first equation will be

I = (a × 4 × 1)/12 × 100

I = 4a/1200 = a/300

The second equation will be

Amount in the account after one month,A

A = I + a/300

A = (300I + a)/300

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

b. 153 students do not participate in sports and seventy-five 12th graders were surveyed