#6 is incorrect
it's 6 7/8
#7 is correct
Answer:
Part 1)
-----> 
Part 2)
------> 
Part 3)
-----> 
Part 4)
-----> 
Part 5)
------> 
Step-by-step explanation:
Part 1) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Convert to mixed number

Part 2) we have

To calculate the subtraction eliminate the parenthesis first

Part 3) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Eliminate the parenthesis

Convert to mixed number

Part 4) we have

To calculate the subtraction eliminate the parenthesis first

Part 5) we have

To calculate the subtraction convert the mixed numbers to an improper fractions



substitute

Eliminate the parenthesis

A) A=500(1+0.015)^t
b)800=500(1.015)^t
800/500=1.015^t
t=log(800/500)/log(1.015)
t=31.6 years
Given:
- Bought n items of product A at 1/5 rs each
- bought n items of product B at 1/4 rs each
He mixed the two items and sold each at 2/9 rs each.
He lost 3 rs in the above batch of articles.
Solution:
revenue = 2n* (2/9) rs = 4n/9 rs
cost = n/5+n/4 rs = n(1/5+1/4)
Profit = revenue-cost = 4n/9-n(1/5+1/4) = -3 rs
Solve for n
4n/9-n(1/5+1/4) = -3
factor out n
n(4/9-1/5-1/4)=-3
n(80-36-45)/180=-3
-n/180=-3
n=3*180=540
Total number of products bought
= n+n = 540+540 = 1080