Question

fruit seller had arranges apples in the following manner 18 apple in the bottom 17 in the next row 16 inthe row next to it .solve it how many rows 170 apples place and how many apples in the top row​

Answer 1

Answer: 17 Rows, 2 apples in top row

No. of apples in bottom row = 18

No. Apples decreasing per row = 1

This forms an AP

No. of apples to be counted = 170

Therefore,

170 = $\frac{n}{2}*(2*18 + (n-1)(-1))$

Solving this gives n = 17 and n = 20

N cannot be equal to 20 as max no. of rows possible is 18

So, n = 17

Answer 2

18 17 16.......... 170

Answer:

a=18 d=a2-a1=17-18=-1. An =170

By using formula method an=a+(n-1)d

170=18+(n-1)-1

170=18-1n+1

170=19-1n

170-19=-1n

151 - 1n

N=151/1

Therefore n=151

There are 151 apple in the top row