The sum of the first natural number and 0 is 1, the sum of the first two natural numbers and 0 is 3, the sum of the first three natural numbers and 0 is 6, and the sum of the first four natural numbers and 0 is 10. which explicit formula generates the sum of the first n natural numbers and 0?

a) n(n+1)/2
b) 2n-1
c) n(n+4)/4
d) 3n-2

What is the measure of the smallest angle in the diagram? 15 29 32 45

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 3 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30∘c on monday, but decreased at a constant rate in the next 3 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

Ican interpret and represent the remainder in division calculations sensibly for the context (eg if we wont to know how many 40 seat buses will be needed to transport 170 students for on excursion, we divide 170 by 40 and realise buses and another smaller vehicle to that we need 4 transport 10 more students) solve the following questions. show your work! 11) the zoo had 420 butterflies that needed to be transported to a new enclosure. the boxes that the butterflies would be moved in only hold 80 butterflies in each. how many boxes would they need? 2 12) each classroom in the school can have exactly 25 students, if there are 345 students in the school how many full classrooms are there?