A firm has a production function Q = F(K,L) with constant returns to scale, where K is units of capital and L is units of labour. Input prices are r = $2 per unit of K and w = $1 per unit of L. When it produces 5 units of output, it uses 2 units of capital and 3 units of labour. When its long-run total cost is equal to $70, how much capital and laobur it will employ to product how many units of output? What is the long-run average cost?