ASAP, pls help me :( i don’t get these questions

2men and 7 boys can do a piece of working 4 days. it is done by 4 men and 4 boys in 3 days how long would it take for 1man or one boy to do it alone

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?

What three-dimensional solid have 6 rectangular faces, 2 equal bases that are not rectangles and 18 edges