Hi, I'm new. Need some help with this sum. Hoping this question wld benefit most of our kids
1) Nuriz and Adeley bought some pens and erasers. Adeley bought 2/7 of the total number of pens and erasers. Altogether, they bought 40 more erasers than pens. Nuriz bought 3/4 of the erasers and 1/2 of the pens. What was the total number of pens and erasers that Adeley bought?
Method #1
The total number of pens and erasers that Adeley bought was 16.
Method #2
2/7 and 3/4 --> 7*4=28
so the total number of pens and erasers should be the times of 28, like,
#1) 1*28=28 --> wrong, as the total number must > 40.
#2) 2*28=56
#3) 3*28=84
...
Try #2) 56....u can check it out it is the right figure for the total number of pens and erasers, so the total number of pens and erasers that Adeley bought was
(2/7)*2*28 = 16
pens (total) -----> u -------->8
erasers (total) --> u+40 --->48
u+u+40 = 56;
u = (56-40)/2 = 8;
Nuriz bought 3/4 of the erasers and 1/2 of the pens. ==>
Adeley bought 1/4 of the erasers and 1/2 of the pens.
pens (Adeley) -----> (1/2)*8 ----->4
erasers (Adeley) --> (1/4)*48 --->12
4+12=16 <==> (2/7)*56=16
Thank you vm...Although I'm still a little confused on the methods, I hope my son wld be able to understand your steps.
