Hours spent on:
Maths = 2x
English = x
Social-studies = x
3 ≥ y ≥ 2
y = 2x+x+x
y = 4x
3 ≥ 4x ≥ 2
3/4 ≥ x ≥ 1/2
3/4 hr = 45min
1/2 hr = 30min
2 × 45min = 90min
Answers:
The minimum time she can spend on english homework is 30min.
The maximum time she can spend on Social Studies is 3/4 hr (45min).
The maximum time she can devote to Math is 90min.