A trader paid a debt in 6 weekly installments as follows. The first week he pays N2, the second twice this, the third three times the first and so on. How much was the debt?
Show workings
First week: N2
Second week: 2 x N2 = N4
Third week: 3 x N2 = N6
Fourth week: 4 x N2 = N8
Fifth week: 5 x N2 = N10
Sixth week: 6 x N2 = N12
Total debt = N2 + N4 + N6 + N8 + N10 + N12 = N42