Mrs Ma baked some biscuits of three flavours, which were apple, cheese and strawberry. She baked twice as many apple biscuits as cheese biscuits and thrice as many strawberry biscuits as apple biscuit. Given that she baked 75 more strawberry biscuits than cheese biscuits, how many biscuits did she bake?
Number of cheese biscuits = 1 u
Number of apple biscuits = 2 u
Number of strawberry biscuits = 3 x 2 u = 6 u

Number of more strawberry biscuits than cheese biscuits
= 6 u - 1 u 
= 5 u

5 u = 75

1 u = 75 ÷ 5 = 15

Number of apple biscuits
= 2 u
= 2 x 15
= 30

Number of strawberry biscuits
= 6 u
= 6 x 15
= 90

Total number of biscuits that he baked
= 15 + 30 + 90
= 135

Answer(s): 135