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The first floor of an ancient japanese tower has 150 steps. Each floor above has 5 fewer floors than the previous. So, the second floor has 145 steps, the third 140 etc. How many floors does the tower have if the final floor has 30 steps leading to it.

Note this is an arithmetic series problem, so we use the equation: x_n= a + d(n-1).
Number of steps on the first floor is 'a', i.e. a = 150.
Difference in the number of steps on each ...

Answered by Joel F. • Maths tutor

2960 Views

Identify which 2 of the following processes involve an exothermic change: melting, boiling, freezing, deposition and sublimation

An exothermic reaction involves an output of heat, so heat is lost overall. This would mean that boiling and melting are definitely not exothermic as they involving putting in heat. Free...

Answered by Ellen S. • Chemistry tutor

5834 Views

Integrate (12x^5 - 8x^3 + 3)dx giving the terms of the answer in the simplest terms

Integration is essentially differentiation in reverse! So in the simpler cases instead of multiplying by the power of x and subtracting one from the power of x, you add one to the power of x and divide by...

Answered by Ellen S. • Maths tutor

6224 Views

How do I remember the differences between the the two tenses; the imperfect and preterite?

This is the way I always remember the difference. The preterite tense is the past. The imperfect tene is the ongoing past. The preterite tense means that an action in the past has finished. For example, ...

Answered by Clara B. • Spanish tutor

2468 Views

(C3) Show that 4csc^2(x) - cot^2(x) = k can be expressed as sec^2(x) = (k-1)/(k-4) where k != 4

The student can answer this in several ways. One using the simple, known identities csc= 1/sin, cot=1/tan, sec=1/cos, tan=sin/cos, sin^2 + cos^2 = 1 and basic algebra is the following:
4csc^2 - cot^2...

Answered by Fearghus H. • Maths tutor

3496 Views