Question

12, 144, 96, 120, 168
7. The product of two numbers is 1600 and their LCM is 160. Find their HCF.
8. Find the greatest number that divides 120 and 144 without leaving a remainder.
9. Two strings of length 285 cm and 345 cm are to be cut into small pieces of equal lengths.
What will be the maximum length of each piece?
10. Three bells ring at intervals of 10, 15 and 20 minutes respectively. If they ring at 11 am
together, then at what time will they ring together next?
11. Find the smallest number which when divided by 143 and 275, leaves a reminder 7.
(Hint: Find the LCM of 143 and 275. The required number will be LCM + 7.)
12. What is the greatest number that can divide 664 and 170 with remainders 1 and
2 respectively? (Hint: Find the HCF of (664 - 1) and (170 - 2).
13. Traffic lights at three different road crossings change after every 1 minute, 1 minutę
20 seconds and 2 minutes respectively. If they change simultaneously at 12 noon, at
what time will they change together again?​

Answer 1

Answer:

Step-by-step explanation:

7. The product of two numbers is 1600.

LCM =160

HCF=?

WE KNOW,

product of 2 numbers=HCF x LCM

$160=1600$ x$HCF$

$HCF= \frac{1600}{160}$= 10

HCF=10