7th Grade Challenging Math

761) Jenny is 64 inches tall. She
is standing next to a lamp post on a sunny afternoon. Her shadow is 4 feet long.
At the same time shadow of the lamp post is 10 ft long. How tall is the lamp
post? (1 foot is 12 inches.)
762) The small square is 100 square cm. What is the area of the large square?
763) The small square is 100
square cm. What is the area of the purple part?
764) Max has some
spiders and iguanas. There are 20 heads and 104 legs in all. How many spiders
and iguanas are there? Spiders have 8 legs.
765)
It takes 4 workers 3 days to assemble 360 car seats. How long does it
take 3 workers to assemble 900 car seats? Assume all workers assemble car seats
at the same speed.
766) Mario
has 3 red marbles and 3 blue marbles in a box. He picks two marbles randomly
without looking.
a) What is the probability that both marbles are red?
b) What is the probability that both marbles are the same color?
c) What is the probability that he picks one blue and one red?
767) Jim has 3 red marbles and 3 blue marbles in a box. Jim picks three marbles
randomly without looking.
a) What is the probability that he picks all 3 blues?
b) What is the probability that he picks all 3 of the same color?
768) Jane flips a coin 5 times.
What is the chance she will get all five heads?
769) Multiple
choice problem:
What is the
approximate value of 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + ......
a) 2; b) 3;
c) 1; d) 1.5
770)
Tom flips a coin 3 times.
(a) What is the chance that he will get 2 heads?
(b) What is the chance that he will get at least two heads?
(c) What is the chance he will get at least 1 head?
More challenging math problems for seventh grade:
15 610 1115 1620 2125 2630 3135
3640 4145 4650
5160
6170
7180
8190
