Nickels are 5 cents, and dimes are 10 cents.
(By luck..) eventually you can have 12 dimes, meaning you have 120 cents, or $1.20 ... 20-12=8.. meaning you used 12 dimes and are missing 8 more coins. which means you can have 8 nickels which is 40 cents. 120+40=160 cents or $1.60
Hope this helped.
He is 38 kg.
I'll use only the first letters of their names, to make it simpler:
S+L=54.75
S+M=105
M=4L
S+4L=105
105-54.75=4L-L=3L
L=50.25/3=16.75
S=54.75-16.75=38