Question 458795
a) {{{2^2 + 5^2 = 4 + 25 = 29}}}

b)  Find the lcm of 1080 and 1350:
{{{1080 = 2^3*3^3*5}}} and {{{1350 = 2*3^3*5^2}}}

==> LCM is {{{2^3*3^3*5^2 = 5400}}}

Hence Siti has to buy 5400/1080 = 5 packets of yellow buttons, and 
5400/1350 = 4 packets of green buttons.  (These give the least number of packets for each color.)

c)  100/5 + 1 = 21 trees