Question

The qualities of these mangoes (is/are) delicious

Answer 1

$\huge{\underline {\underline {\green{Answer}}}}$

The qualities of these mangoes are delicious.

$<font color = "red"><marquee>❤❤❤Thanks❤❤❤</marquee> </font>$

Answer 2

Answer: The qualities of these mangoes are delicious.

Explanation: If you use, quality then it will be 'is'. Because we will judge this sentence by 'quality' word, not by mangoes.