Question

Please help me with this sum.​

Answer 1

Step-by-step explanation:

"The series

160,140,120,100,80,60,40

Given:

Rs. 700 for seven cash prizes

To find:

The series

Solution:

Consider the series as an AP series

where

First element = a

Common difference(d) = - 20

Number of elements(n) = 7

Sum of all elements(s) = 700

$s = \frac{n}{2}(2 a + (n - 1) d)s= </p><p>2</p><p>n$

$(2a+(n−1)d)</p><p></p><p>700 = \frac{7}{2}(2 a + (7 - 1)( - 20))700= </p><p>2</p><p>7$

(2a+(7−1)(−20))

200 = 2 a - 120

320 = 2a

a = 160

Each term will be 20 less than the previous one.

Hence the series will be

160,140,120,100,80,60,40."

Answer 2

Answer:

1st prize is ₹160

2nd prize is ₹140

3rd prize is ₹120

4th prize is ₹100

5th prize is ₹80

6th prize is ₹60

7th prize is ₹40

160+140+120+100+80+60+40=700

I hope this helps: