jacob is 39 years old . he is 3 times as old as his brother . how old will jacob be when he is twice as old ?
"j = 39 ; j = 3 b ; b = 39 / 3 = 13 ; twice as old so b = 13 ( now ) + ( 13 ) = 26 ; jacob is 39 + 26 = 65 answer : c"
multiply(39, 3)