Answer:
Julius: 52
John: 47
Grace: 51
Explanation:
Let marks scored by Julius, John and Grace be x, y and z respectively
From the information given,
"Julius scored 5 more marks " → x = y + 5 (1)
"who in turn scored 4 marks less than Grace" → y = z - 4 (2)
Substitute y = z - 4 in equation x = y + 5
→ x = (z-4) + 5
→ x = z - 4 + 5
→ x = z + 1
"The total mark scored by the three students was 150":
x + y + z = 150 (3)
Substitute x = z - 1 and y = z - 4 in equation (3):
← (z + 1) + (z - 4) + z = 150
→ z -+ 1 + z - 4 + z = 150
→ z + z + z + 1 - 4 = 150
→ 3z - 3 = 150
→ 3z = 150 + 3 = 153
→ z = 153/3 = 51
So Grace's mark was 51
John's mark y = z - 4 = 51 - 4 = 47
Julius' mark x = y + 5 = 47 + 5 = 52
Substitute for y from (2) in (4):
2(z - 4) + z = 145
2z - 8 = 145