In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No Error'.

We are increasingly living in (A) / digital networks, spending (B) / an average of 11 hours a days on screens (C) /No error(D)

Find the HCF of 36, 108, and 156.

Find the least number which when divided separately by 15, 20, 35 and 45 leaves 3 as remainder in each case?

The LCM of two numbers is 12 times their HCF. The sum of LCM and HCF is 403 and if both the number are smaller than their LCM. Find both the numbers?

The ratio of two number is 6 : 5 and their HCF is 15. So find and their LCM?

The sum of two numbers is 65 and their HCF is 13. Total number of such pairs of numbers is?     

The LCM of two numbers is 40 times its HCF. If the product of the numbers is 1440, find their HCF.

LCM of 21 ⁵ , 21 ¹⁰ and 21 ¹⁵ is?

(1). 21 ⁵

(2). 21 ¹⁵

(3).21³⁰

The L.C.M of a² – 2a – 3 and a³ + a² + a + 1 is