"Think" is only the fifth duet between a solo male and female (
with each artist sharing lead credit) to top the chart, following Keith Urban and Miranda Lambert's "We Were Us" (2013), Brad Paisley and Carrie Underwood's "Remind Me" (2011), Anita Cochran and Steve Wariner's "What If I Said" (1998) and Reba McEntire and Vince Gill's "The Heart Won't Lie" (1993).
Source.
Carrie, Miranda, and Cassadee the new Country Trinity!