25% taller means that 100%+25%=125% the height of someone. As a result, Will is 25% taller than Wanda, so Will's height is 125% of Wanda's height. For example,
If Wanda is 150 feet tall and Will is 25% feet taller than Wanda, which means that Will is 125% of Wanda's weigh, so
Will's height=
150×125%=187.5 feet. Hope it help!