Answer:
There are 80 marks in total.
Step-by-step explanation:
Let the number of total marks be
.
The percentage score of the student can be written as the ratio
.
However,
.
Equating the two:
.
Cross-multiply (that is: multiple both sides by
, the product of the two denominators) to get
.
.
In other words, there are 80 marks in total.
Answer:

Step-by-step explanation:

Answer:
2 
Step-by-step explanation:
Change the mixed numbers to improper fractions
(
-
) +
← the LCM of 2 and 3 is 6
=
-
+ 
=
-
+ 
=
+ 
= 
= 
= 2 
3 sodas cost $2.97 +.15 tax total $3.12