Hi, I need help with question a)

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of

Jessie and bob are financing $425,500 to purchase a house. they obtained a 30/8 balloon mortgage at 6.55%. what will their balloon payment be?

Of the following, which statement or statements accurately reflect a way in which credit can be safer than cash? i. if your credit card gets stolen, you can cancel it and get your money back. ii. it is harder to lose a single credit card than a large number of bills. iii. if a merchant does not honor the agreement, you can call the credit company and dispute the charges. a. i and iii b. ii only c. iii only d. i, ii, and iii