Top answers

You are given a sequence of numbers: -2, 12, 32, 58, 90, ... Work out the 7th term in this sequence.

This is a question from Higher Tier and involves 1) realising that 2nd difference is a constant: 6. 2) knowing that constant 2nd difference implies the sequence is quadratic. 3) remembering or proving that c...
MV
Answered by Maxym V. • Maths tutor
5827 Views

Find the constant term in the binomial expansion of (3x + 2/(x^2))^33

Recall that the general term in the binomial expansion of (x+y)^n is (nCr)(x^n-r)(y^r), so by the binomial theorem, the entire expansion is the sum of these terms from r = 0 to n. In this case, n = 33, the f...
EG
Answered by Elias G. • Maths tutor
8850 Views

Event A: a customer asks for help. Event B a customer makes a purchase. We know: p(B) = 0.2 and p(A) knowing that he has asked for help is 75%. What is the probability of a customer to ask for help and make a purchase?

If we right down all we have here we get:P(A) = X P(B) = 0.2 P(AIB) = 0.75 (P(A) knowing B). And we are looking for P(ANB). We have to use the formula of P(AIB) = P(ANB)/P(B). If we rearrange the equations, ...
DA
Answered by Dan A. • Maths tutor
3178 Views

What's the best strategy when approaching a maths problem?

First of all you need to understand that not every problem can be solved by sistematically applying the same set of steps or rules: sometimes you need to come up with different ways. In order to do that, you...
MI
Answered by Michele I. • Maths tutor
3607 Views

Factorise x^2 + 5x + 6

We are trying to get to the form of x 2 + 5x + 6 = ( x + a)(x + b)6 must also factorise as 6x1 or 3x2 Let's focus first on the x terms : 5x is the sum of ax + dbx and the coefficient of these two must be fac...
MG
Answered by Maëlle G. • Maths tutor
4384 Views