Asap I need help help me to answer this please

Given that 1/21 + 5/21 + 11/21 + a/b = 1. where a and b are positive integers such that a/b is in simple friction, find the value of a + b.​

Agarden inside a park has the shape of trapezoid.its bases are 10 meters and 16 meters.the perpendicular distance between these is 12 meters.what is the area of the garden

How to solve using ratio proportion? ​