52) 115-3=112 that were given away
Now divide 112 by each, seeing if they give you a non mixed number.
The only one that would give you a full number would be 28. So there are 28 kids in his class.
54) 19-4=15
Now double 15 since he sold half, so he started with 30 stamps originally.
56) 500-2*=324
-2*=-176
age=88
= 7/8 − 1/5
= ((7 × 5) − (1 × 8)) / (8 × 5)
= (35 - 8) / 40
= 27/40
= 27/40
SO, 27/40 minutes are NOT spend on instructions.
Hope I helped:P
2 2/3 is an answer, your welcome