Question 1100257
a/2=3b/8
a=3*(b-240)

a/2=3b/8
3*(b-240)/2=3b/8
(b-240)/2=b/8
b-240=b/4
4*b-4*240=b
3*b=4*240
b=4*80
b=320

a=3*(b-240)
a=3*(320-240)
a=3*(80)
a=240
check
remove 240 from 320 in box b is 80
box a now has 240 and box b 80
240 is three times 80

This second question is unclear. After or before the 240 are removed? 
How many sweets would have to be taken out from box a so that there would be 1/4 as many sweets in box a as in box b.