Solve this problem.

brianna paid $18.89 for a pair of sandals. she bought a pair of hiking boots that cost $12 more than her sandals. how much did brianna pay for the two pairs of shoes?

how can estimation be used to make sure the answer is reasonable?

a.
brianna paid $42.89.
estimation: $19 + $12 = $31
$31 + $12 = $43
brianna paid about $43 for the shoes.

b.
brianna paid $25.78.
estimation: $19 – $12 = $7
$19 + $7 = $26
brianna paid about $26 for the shoes.

c.
brianna paid $49.78.
estimation: $19 + $12 = $31
$31 + $19 = $50
brianna paid about $50 for the shoes.