Question

A men can do a work in 14 days and working together a and b can do the same work in 10 days. in what time can b alone do the work ?

Answer 1

$(1 \div a) + (1 \div b) = (1 \div a \: and \: b)$
$(1 \div 14) + (1 \div b) = (1 \div 10)$
b=35days