What is a cell? Also how is the cell made

Abby buys 4 pencils and 2 erasers for $3.58. Micheal buys 1 pencil and 6 erasers for $2.49 what is the cost of 1 pencil and 1 eraser?

Hal is mixing bug spray for his roses. He has one gallon with a mixture of 90% water and 10% chemical. However, he needs a mixture that is 96.5% water. How much water should be added to the mixture to make it 96.5% water?

On Wednesday afternoons, eight men play tennis on two courts. They know ahead of time which four will play on the north court and which four will play on the south court. The players arrive randomly at the tennis courts.

Complete this 5x^2+16x+11

Briana bought 3 bottles of ketchup and 2 bottles of mustard and for $11.85. Logan bought 2 bottles of ketchup and 5 bottles of mustard for $13.73. Find the cost of each.

2 (-1-1) - (-1+5) - 7 (2 (-1) - 1)

There are a total of 20 lions, tigers and bears. If the number of tigers is 2 more than the number of lions and the number of bears is 1 more than the number of tigers, find the number of each.

Is it possible to carry a 9 foot piece of lumber in an enclosed rectangular trailer that is 4 feet by 8 feet by 4 feet?

Find the next term of given sequence. 11, 37, 127, 445, 1591, ...

Larry bought 2⁄3 pound of red potatoes and 3⁄4 pound of golden potatoes. How many pounds of potatoes did he buy in all?