25 points! ! i need ! you have 5 attempts and if you are wrong, i will let you know so you can make corrections and i get the right answer.

Obviously, if he were to only maximize his income he would put all money on the higher interest. But to reduce the risk he will balance the investment. He will put a fraction a (between 0 and 1) of the 710000 on 1% and the rest (1-a) on the 4.5%.  Both interests together must then satisfy to add up to 18000.

So written as an equation:

I am not going to solve step by step assuming you can solve for a (if not let me know) but the solution is

So that means he should put

on the 1% account, and the rest 311429 on the riskier 4.5% account.

the answer is d

step-by-step explanation:

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls