Question

5:
2 taps can fill a tank in 20 and 30 hr, respectively. If both taps are used, how
much time will be needed to fill the tank ?
2 नल क्रमश. 20 और 30 घंटे में एक टेंक को भर सकते हैं यदि दोनों नल का प्रयोग किया जाता है
तो टेक को भरने के लिए कितने समय की आवश्यकता होगी ?
10 hrs/ad
b) 12 hrs/घटे
15 hrs/uty
20 hrs/ घंटे
d)
A dealer sold two types of goods for Rs 10,000 each. On one of them, he lost 20%
and the other he gained 20% What was his gain or loss percent in the entire
transaction ?
36:
एक डीलर ने दो प्रकार के सामान को 10000 रुपए प्रत्येक के भाव पर बेचा जिसमें से एक में 200
की हानी हुई एवं दूसरे में 20% का लाभ हुआ | पूरे लेन देन में लाभ या हानी कितने प्रतिशत की
थी।
4% gain / 19
2% loss/हानि
b)
d)
4% loss / हानि
20% gain / 191
The average age of three boys is 15 years. If their ages are in the ratio of 357
innost hoy (in years).​

Answer 1

Answer: 12 hour

Step-by-step explanation:

A=20 hr

B=30 hr

take LCM of A and B

60 LCM = total work

efficacy of A= 60/ 20 =3

efficacy of B =60/30 = 2

total efficacy = 3 + 2= 5

total time=  total work/ total efficacy

total time= 60/5 = 12 hour