1

x = LinRange(0, 2pi, 9)
v = sin.(x)
xq = LinRange(0, 2pi, 25)
vq = interp1(x, v, xq)
plot(x, v, "o", markersize = 5.5, xq, vq, ":.")
xlim([0, 2pi])

2

function f(x)
s = 0
str = string(x)
for z in str
s = s + parse(Int64, z)
end
return s
end

i = 7
s = f(i)

while s <= 20
i = i + 7
s = f(i)
end

print(i)