Question

If the number from 5 to 85 which are exactly divisible by 5 are arranged in descending order which would come at 11th position

Answer 1

Required numbers are the numbers which are divisible by 5 and are situated between 5 and 85.

Thus the required numbers are 10, 15, 20, 25,.....80, as all of them are divisible by 5 and are in between 5 and 85.

Now, we have to count the numbers.

Before that, on observing the situation, we can say that all the required numbers are in AP. In this Arithmetic Sequence, first term is 80 ( first number between 5 and 85 which , in descending order ) with a common difference of - 5( while taking in descending order ) since all numbers are the consecutive multiples of 5.

From the properties of arithmetic sequence, we know

• nth term = a + ( n - 1 )d, where a is the first term, n is the number of terms and d is the common difference between the terms.

In the given question, first term is 80 and common difference between the terms is - 5.

Substitute 11th term in place of nth in the formula : -

Thus,

= > 11th term = a + ( n - 1 )d

= > 11th term = 80 + ( 11 - 1 )( - 5 )

= > 11th term = 80 + ( 10 )( - 5 )

= > 11th term = 80 - 50

= > 11th term = 30

Hence the required numbers is 30 which should come between 5 and 85 on moving in descending order from 85 on 11th place.

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Answer 2

Answer:

Step-by-step explanation:

The required numbers in descending order are :

85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, 5.

The eleventh number from the bottom is 55.