) In a pizza restaurant ,you get a basic pizza with two toppings cheese and tomato .you can also make up your own pizza with extra toppings .you can also choose from 10 different toppings .e .g olives,ham,mushroom,salami etc .ross wants to order a pizza with two different extra toppings .how many different combinations are possible ?
a)100 b)1024 c)90 d)45

• 10C2=45... There are 10 option and wee need to choose 2
• 13 years agoHelpfull: Yes(10) No(2)
• 
  n*(n+1)/2
  9*(9+1)/2=9*5=45
  
  
• 13 years agoHelpfull: Yes(3) No(2)
• I think the question clearly says find the number of combinations.... Here arrangements of toppings doesn't matters ...
  So it should not be 10P2 and rather it should be 10C2.
• 13 years agoHelpfull: Yes(2) No(1)
• i think its 90 bcz first toppings can b chosen from 10 different varites and and the next one can b chosen from 9 so, its 10*9=90
• 13 years agoHelpfull: Yes(0) No(2)
• the answer will be 10p2=factorial 10/factorial 8=90
• 13 years agoHelpfull: Yes(0) No(8)
• FIRST TOPPING CAN BE SELECTED FROM ANY 10 OF THE AVAILABLE TOPPINGS. HOWEVER,SECOND TOPPING CAN BE CHOSEN FROM 9 AVAILABLE TOPPINGS TO MAKE IT DIFFERENT.
  
  SO, 10X9=90 ANS
• 13 years agoHelpfull: Yes(0) No(2)
• 10c2 =45. Then there are 2 pizzas so 45 *2 =90
• 5 years agoHelpfull: Yes(0) No(0)