What number goes into 78 and 19

Chen spent 7 hours at school on Friday he spent 30 minutes at lunch 50 minutes at a school assembly and the rest in class how much time did Chen spend in class

Two riders are in a bike race. The second rider starts half an hour late but rides 4 miles per hour faster than the first rider. If they both finish 3 hours after the race starts, how fast are they each riding?

C'est quoi un square root?

What is 7 0 0, 0 0 0 + 9, 0 0 0 + 6 0 + 7 700,000+9,000+60+7700, comma, 000, plus, 9, comma, 000, plus, 60, plus, 7 in standard form?

How do you write this 11,465.2 billion in numbers?

What is the minimum value of P=24x + 30y given the constraints

The cylinder shown has a volume of 54π cm3. In a similar cylinder, the dimensions have been doubled. What is the ratio of the volumes (small to large) ?

A sequence is defined that the first term is 4 and each term after the first term is found by adding 4/5 to the preceding term. What is the 8th term of the sequence?

A scientist is investigating a cell. The cell has a membrane thickness of 7.*10-8 m and has a surface area of 4.*10-8. The initial concentration inside the cell is n (0) = 0.6 M, and the scientist later observes that an (0.2) = 0.77 M.

13[42 - (2+4) second power]