Chinedu sat down to do his homework, which included 30 math problems. he solved 2 problems each minute. let f(n) be the number of problems left for chinedu to solve at the beginning of the 9 th minute.

14

Step-by-step explanation:

If he is solving 2 problems per minute and 8 minutes have passed, he has solved

2*8 = 16  problems

There are 30 problems and he has solved 16

30-16 = 14

There are 14 problems left to solve at the start of the 9th minute

She must buy 50 candies that cost 80 cents per pound must she buy to make a $1 candy mix if she already bought 50 pounds of candy for $1.20 per pound. This problem can be solved by using a simple algebra equation to find the addition candy number which stated as $1 = $1.2*50+$0.8x/(50+x). This equation will result in 0.2x = 10, therefore, x = 50 which represents the additional candy needed.