A student did 3 5 of his homework and another 8 problems. then his father came and did one fifth of his homework and the remaining 7 problems. how many problems did they solve together?
Let’s assume the number of problems as P
Student did his homework = (3/5) P + 8
Father did the homework = (1/5) P + 7
So the sum of the both equations is equal to P
=> (3/5) P + 8 + (1/5) P + 7 = P
=> (4/5) P + 15 = P
=> 4P + 75 = 5P
=> P = 75
Problems they solve together are 75 problems.
