As an estimation we are told 5 miles is 8 km.
Convert 55 miles to km​

88 km.

Step-by-step explanation:

If 5 miles is 8 km,

55 miles is 88 km.

What you need to do is 55/5 = 11.

Then multiply that 11 to 8.

11 * 8 = 88.

Basically, if you are multiplying 5 by 11 to get 55, you need to multiply 8 by 11 to get 88.

the number of possible combinations is given by

c(18, 3) = 18! /(3! (18- = 18·17·16/(3·2·1) = 816 . . possible combinations

there are 18 ways to choose the first one; 17 ways to choose the second one, and 16 ways to choose the 3rd one. the same 3 students can be chosen in any of 3! = 6 different orders, so the product 18·17·16 must be divided by 6 to get the number of possible combinations in which order doesn't matter.